Small Wars Journal

Gray Dismay: A Strategy to Identify and Counter  Gray-Zone Threats in the South China Sea

Mon, 06/06/2022 - 9:31am

Gray Dismay: A Strategy to Identify and Counter  Gray-Zone Threats in the South China Sea


By Matthew H. Ormsbee


“The United States is an Indo-Pacific power.”[1]


I. Introduction

            The current state of American military dominance signals credibility of force but also diverts adversaries’ efforts from conventional war to ambiguous threats below the threshold of war—so-called gray-zone threats.  Regrettably, such tactics in the gray zone are on course to proliferate as adversaries largely acknowledge conventional overmatch with the United States.[2]  Rather than risk political harm and potentially massive losses in traditional war, competitors will take actions in the gray zone to counter American influence and authority through non-military measures that erode the legitimacy that the United States has cultivated since the Second World War.[3]  Unquestionably, these measures are challenges to American national security.  Left unchecked, they will diminish American dominance and the United States will slowly concede its authority and good will.

            The People’s Republic of China poses the most substantial global threat to American security interests as Chinese actors tighten their grip on maritime features in the South China Sea to the exclusion of neighboring states.[4]  This is one of the key problems of our day: reining in Chinese expansionism while bolstering ally efforts to stand their ground and promote regional stability.  The United States can most effectively counter Chinese gray-zone tactics by strengthening international legal agreements and response obligations with allies in the Indo-Pacific region.  In practice, this means focusing on bilateral defense treaties—turning first to our treaty with the Philippines, as the oldest American security alliance in the Indo-Pacific—to increase readiness, draw clear lines in the sand, and offer peace of mind to long-time partners.  Stronger ties and clearer commitments will build the foundation for assurances that China will not trample neighbors’ sovereign rights or maritime entitlements; if China attempts to do so, the United States will steadfastly support its allies. 

This paper puts forth several proposals and a bold strategy to realize these important aims.  Very similar strategies may be adapted from the proposals in this paper to counter gray-zone offensives from other competing states.  After all, China is the primary security challenge for the United States, but it is far from the only competitor to employ gray-zone tactics, particularly as Russian forces employed gray-zone threats prior to the invasion of Ukraine in early 2022.  The proposal to reinvigorate international legal agreements for new times can be adapted to the many defense treaties and partnerships the United States maintains worldwide.  Doing so would send the clearest signal of a zero-tolerance approach to gray-zone threats.

II. Gray-Zone Threats

The White House issued its Interim National Security Strategic Guidance in March 2021, clarifying the aims and focal points of the Biden administration’s national security strategy.[5]  Of note, the President specifically called on the nation to “develop capabilities to better compete and deter gray zone actions.”[6]  This direct appeal acknowledges the importance of countering gray-zone threats, which have become “revisionist regimes’ preferred approach for seeking political advantages against the United States and its allies.”[7]

Gray-zone tactics are ambiguous, belligerent, and coercive actions intended to achieve strategic aims without military conflict.[8]  Such tactics are labeled “gray” because they do not fall within the traditional black-or-white dichotomy of war and peace; instead, they fall somewhere in the undefined middle.[9]  Gray competition encompasses a “zone” because the realm of ambiguous tactics is broad, numerous, and not easily defined.[10]  Because gray-zone tactics fall short of traditional war, they raise complex and novel issues for policy makers, lawyers, and military professionals.


            Even near-peer adversaries like China are wise to avoid head-to-head military conflict with the United States following the decisive and well-documented American victory in the 1991 Gulf War.[11]  No logical state actor would seek to confront the United States in traditional warfare in the aftermath of that notable conflict, in which the United States achieved a quick and decisive victory.[12]  The United States has effectively deterred the high-end fight—for now.  Perhaps as a result, the decades-long conflicts in Iraq and Afghanistan are evidence that adversaries have embraced a new model of conflict that features gray-zone methods and promises challengers a no-lose outcome.[13]  As adversarial regimes gradually prefer cold wars to hot wars, adversaries are embracing the gray zone, with China leading the charge.[14]

III. Chinese Aggression in the South China Sea

            China favors tactics within the gray zone due to the ambiguous nature of such actions, by which “action occurs so gradually that the adversary never concentrates against it.”[15]  For its part, Australia, as a staunch ally of the United States in the Indo-Pacific region, reaffirms in its 2020 Defense Strategic Update that China’s belligerent gray-zone coercion furthers a Sinocentric Indo-Pacific Order.[16]  In particular, China’s maritime activities in the South China Sea represent gray-zone activities meant to badger and coerce several allies of the United States, particularly the Philippines.  China’s unlawful encroachments into Philippine territorial waters have harassed the Philippines and undercut reasonable expectations of sovereignty and entitlements, even as the Philippines won a stunning and historic arbitral award against China at the Permanent Court of Arbitration in 2016.[17]

On several occasions, China has invaded what the Philippines views as territorial waters in the South China Sea, cut off Philippine fishing boats from these waters, and occupied land features in the region that are claimed by the Philippines.[18]  More recently, the Philippine Government condemned China’s swarming of Thitu Island in 2019, alleging that China’s actions were a “clear violation of Philippine sovereignty, sovereign rights and jurisdiction, as defined under international law including the 1982 United Nations Convention on the Law of the Sea (UNCLOS).”[19]  While falling short of war, such actions are clear acts of hostility meant to challenge Philippine maritime claims and chip away at any Philippine resistance.

            As recently as 2021, vessels belonging to the Chinese Coast Guard and Chinese People’s Liberation Army chased Philippine journalists away from the Spratly Islands.[20]  Even as the journalists were in a civilian boat on their way to the Philippine-occupied Second Thomas Shoal, and within the 200-nautical-mile Exclusive Economic Zone (EEZ) of the Philippines, the Chinese vessels approached and gave pursuit for an hour before the journalists were close to the Philippine mainland.[21]  This aggressive and unprecedented harassment took place during a time of particular unease between the Philippines and China from December 2020 to March 2021, as China amassed 220 Chinese fishing and military vessels around Whitsun Reef, an unoccupied reef that is 170 nautical miles west of Palawan.[22]  Whitsun Reef is jointly claimed by the Philippines, China, and Vietnam.[23]

            Philippine leaders appear to be exasperated because international laws have provided insufficient protection from Chinese state and non-state actors, failing to police and limit a growing threat to Philippine maritime claims.[24]  Philippine citizens are similarly exasperated: fishermen from the Palawan region of the Philippines have filed suit at the Philippine Supreme Court, requesting that government leaders enforce the domestic Fisheries Code, which would restrict Chinese vessels from damaging Philippine coral reefs and endangering local species.[25]  Such a measure is the surest sign that Philippine citizens are frustrated but that the national government is hamstrung to rein in Chinese abuses.

            Responses from the Philippine government are constrained because the nation has long suffered from a paradoxical defense posture.  On the one hand, the Philippine government maintains a decades-old bilateral defense treaty with the United States, which possesses the most powerful conventional military force in the world.[26]  On the other hand, the treaty does little to assuage Philippine leaders as China takes ever bolder actions in the South China Sea.[27]  Furthermore, Philippine budget constraints have inevitably curtailed military purchases and caused Philippine President Rodrigo Duterte’s threats to China to ring hollow.[28]  As the Philippine government has grown more and more dependent on its allies to provide military assistance, the United States has quietly observed the developing situation without significant intervention.[29]

IV. Mutual Defense Treaty with the Philippines

            The most effective means to identify and counter gray-zone threats is to leverage the United States’ numerous historic alliances, which exemplify a unique strategic advantage that our competitors cannot match.[30]  Key among such alliances is the long-standing partnership between the United States and the Philippines.  Perhaps more than ever, the critical Philippine location and its role in the South China Sea make the archipelago nation indispensable for both Chinese and American strategic planning.[31]  Treaties between the United States and the Philippines represent core international law that states routinely use to obligate themselves to other states and vice versa.[32]  Legal agreements between the two states form the backbone of American national security law as Philippines leaders seek greater defense assurances and China seeks to expand its reach and influence in the South China Sea.[33]

            In 2021, the United States and the Philippines celebrated the seventieth anniversary of their Mutual Defense Treaty (MDT), signed on August 31, 1951, in Washington.[34]  The two nations agreed in Article IV of the MDT that “an armed attack in the Pacific area on either of the Parties would be dangerous to [the] peace and the safety” of both states.[35]  Furthermore, the agreement states that each party would “act to meet the common dangers in accordance with its constitutional processes.”[36]  Unfortunately, the MDT speaks in terms of traditional, conventional offensives (such as armed attacks and responses), while offering little or no guidance on responses to gray-zone tactics that fall outside the traditional model of warfare.[37]  Yet, the Philippines is dependent on the United States for mutual defense more than ever before.[38]  Therefore, lack of clarity in the MDT due to anachronistic provisions is extremely concerning and leaves much room for improvement.

Since the MDT was ratified, the United States has sidestepped questions about whether it would steadfastly adhere to the MDT in the context of non-armed Chinese aggression toward Philippine vessels in contested and even sovereign waters in the South China Sea—much to the dismay of the Philippines.[39]  The relative unpredictability of President Duterte’s tenure has not done any favors for American-Philippine relations or the vitality of the MDT, thus further straining the alliance.[40]  With the terms and viability of the MDT in question, Philippine Defense Secretary Delfin Lorenzana called for the two parties to confer in October 2018 with an eye to whether the treaty was still fully relevant.[41]  The stated goal was to review the legal agreement and decide whether to “maintain it, strengthen it, or scrap it.”[42]  Secretary Lorenzana has signaled concerns with the MDT for years, echoing in 2021 earlier calls to revisit commitments under the treaty and clarify the parties’ obligations.[43]

In early 2019, United States Secretary of State Mike Pompeo met with his Philippine counterpart, Foreign Secretary Teodoro Locsin, Jr., to give assurances to Philippine leaders.[44]  Secretary Pompeo stated that “any armed attack on Philippine forces, aircraft, or public vessels in the South China Sea will trigger mutual defense obligations under Article 4 of our Mutual Defense Treaty.”[45]  The American assurance came at a critical time in which Philippine vessels regularly pleaded for American assistance against Chinese vessels in contested parts of the South China Sea.[46]  Still, the American reassurance left Defense Secretary Lorenzana uneasy in light of the lack of specifics for an American threshold for response.[47]

Without clearer criteria for defining an “attack” on the Philippines—and whether that would include certain gray-zone threats, especially in disputed waters—the American assurance was construed by Philippine leaders as largely meaningless.[48]  Secretary Lorenzana raised a valid concern: gray-zone competition may gradually become more prevalent than traditional warfare, so ignoring gray-zone threats is a sure path to weaker national security.[49]  Any meaningful conversation about the national security of the United States must address how the United States will compete in the gray zone to protect its national security interests.[50]  Ultimately, military and political leaders must reexamine legal agreements to clarify triggering actions and appropriate bilateral responses in the era of gray-zone threats.[51]

V. Reinvigorating Treaty Obligations

            The United States must draft and propose meaningful revisions to the MDT that will address the new paradigm of gray-zone threats and assuage concerns from the Philippines.  Now is the ideal time to prioritize American-Philippine relations as the United States pursues a strategic pivot to foreign policy in Asia.[52]  The United States and the Philippines can start by issuing a joint statement to shore up support for a revised MDT with teeth.  A public declaration of cooperation will serve as deterrence and encourage other allies in the region.  After all, a unified stance and public acts of diplomacy constitute lawful and appropriate gray-zone responses against adversaries.[53] 

Next, the parties must conceptualize a response matrix to clarify gray-zone threat levels.  Revisions to the MDT should feature a tiered system of threats, akin to defense readiness condition (DEFCON) levels or force protection condition (FPCON) levels, with accompanying rules of engagement, criteria for escalation and de-escalation, and transparent consequences if China (or any adversary) crosses a red line.[54]  New GRAYCON levels (depicted below) should be restricted to the least necessary severity and geographic area to counter a gray-zone threat.  While these levels and the corresponding precautions are very much in early draft form (and contain only the general contours of a strategy), a final framework can be structured to ensure that the parties (and adversaries) have clear expectations for gray-zone conflict.


Gray-Zone Readiness Condition (GRAYCON) Levels





Rules of Engagement



Maximum readiness; immediate response

Specific gray-zone threat in progress or just occurred

Proportionate response on-site; use of force/kinetic intervention authorized

Immediate military, diplomatic, and/or economic response


Substantially increased readiness

Predicable or imminent gray-zone threat

Assistance ready to counter identified threat; use of force/kinetic intervention authorized

Military build-up if necessary; strengthened security readiness


Above normal readiness

Small, unspecified, or unpredictable gray-zone threat

Use of force may be necessary as situation develops

Increased intelligence watch


Baseline readiness

No identified gray-zone threat

Use of force not warranted

Minimum recourse


            The United States must squarely address China’s emboldened actions in the South China Sea and declare for the record which Chinese actions are acceptable and which will not be tolerated.  Such clarification is all the more important in light of the atrophied state of the Philippine military: since the end of the Cold War, the Philippine armed forces have been severely drained of materiel and personnel.[55]  Philippine external defense forces are in a dismal state and in urgent need of monetary and arms assistance.[56]  This has severely handicapped any Philippine attempt to counter Chinese actions in the South China Sea and “sapped the Philippine-American mutual defense treaty of its deterrent power.”[57]  Without clarity of treaty, the MDT will languish and both parties may suffer.

            The Philippines and the United States must decide precisely where they will draw the line on Chinese incursions into Philippine territorial waters.  A wise proposal would assure the Philippines that if Chinese vessels trespass into the Philippine territorial sea or contiguous zone (areas closest to Philippine land features), then these invasive acts may be met with force by Philippine military forces, as well as American military forces, as necessary (red zones in diagram).  In addition, Chinese incursions into the Philippine EEZ will be met with joint force if (1) such incursions interfere substantially with the Philippines’ special rights granted under UNCLOS to explore, collect marine resources, and produce offshore energy; or (2) such incursions are so severe and pervasive that they require kinetic intervention to counter such actions because diplomatic appeals have been fruitless (yellow zone in diagram).[58]  Regular and clear communications from military and diplomatic sources will alert China to ongoing concerns with respect to the EEZ.  Finally, the presence of non-hostile Chinese vessels at the continental shelf may be tolerated by parties to the MDT, barring any openly violent acts (green zone in diagram).

Clarity of mutual defense obligations will ease Philippine concerns and alert China that American forces are guaranteed to intervene for particular actions.  Additionally, the parties must embrace the policy that any attack on Philippine armed forces, aircraft, vessels, or other military assets will be deemed an attack on both parties under Article V of the MDT.[59]  Thus, regardless of whether Philippine military assets are in contested waters or squarely on Philippine territory, Chinese gray-zone aggression on military forces should not be justified and will not be tolerated.

On the strategic and operational levels, revisions to the MDT must be driven by a significant shift in American sentiment to China that occurred well after the signing of the MDT.  Namely, since the 1990s, the United States and many of China’s regional neighbors hoped that globalization would benefit China but also turn the nation into a “responsible stakeholder” on the global stage.[60]  If China accepted more responsibility for transnational actions, Chinese attitudes might be transformed to feature greater accountability, including in sovereignty disputes in the South China Sea.[61]  These hopes were left largely unfulfilled and China grew into a viable competitor to the United States in the 2010s.[62]  This series of events has driven a shift in American sentiment toward China and caused the Trump and Biden administrations to take harder stances on Beijing’s “core interests,” as declared by the Chinese Communist Party.[63]  With this strategic shift and historical context, corresponding revisions to the MDT and a warming of United States-Philippine relations are necessary and timely more than ever.

On the tactical level, the United States must internalize a central principle: in gray-zone maneuvers, actors that are government-backed but non-military in nature shall be considered aggressors subject to gray-zone countermeasures.[64]  This means that China’s Coast Guard or maritime militia further China’s gray-zone strategy at their own peril.  Non-state actors are not immune to countermeasures solely by virtue of their status as non-state actors.[65]  Aggressive actions from these entities and others like them may be met with a joint American-Philippine response.  Future guidance accompanying the GRAYCON levels must expand upon such tactical considerations.

A final piece of this proposal encourages a method of forced inquiry-and-response with adversarial states in order to eliminate or reduce the unique element of ambiguity in gray-zone threats.  For example, if the Philippines perceives discrete maritime threats from Chinese actors that fall in the gray zone, Philippine leaders must issue a diplomatic demand that the Chinese explain their purpose for such actions, or else the actions will be construed unambiguously as an aggressive overture to armed conflict.  This paradigm places the onus on the gray-zone actor to (1) clearly admit hostile acts, (2) deny hostile acts and provide supporting evidence, or (3) fail to respond, which would be tantamount to an admission of hostility.  The phrasing of a Philippine demand would be intended to force China to offer reassurances that no pre-war acts were intended or else publicly admit hostile acts.  Either way, by eliminating the element of ambiguity in gray-zone threats, actions are taken out of the gray zone and moved into either the war column or the peace column.

            In the absence of reliable MDT provisions—and with its weakened external defense forces—the Philippines has understandably vocalized frustration with China’s maritime encroachments.  Philippine leaders have had no clear answers for how to deal with incursions on sovereign territory, harassing actions at sea, and lack of Chinese cooperation, leaving the country in a difficult dilemma.  Rather than shelve the MDT altogether, the parties must reinvigorate the 71-year-old legal agreement for modern threats.  The parties can put forth several feasible measures that will signal joint support for certain lines in the sand against Chinese expansionism in the South China Sea.  Ultimately, clarity of legal provisions will bring about a positive ripple effect, which will in turn strengthen American national security.

VI. Counterarguments and Responses

The proposal to make specific and meaningful revisions to the MDT is not without minor drawbacks, though most of these disadvantages can be mitigated or dismissed.  First, while an ambiguous legal agreement can leave the parties in a lurch, it also provides the parties flexibility if commitments are not clearly triggered.  Indeed, some degree of flexibility for the parties’ obligations can be beneficial and is a somewhat common feature in defense treaties more generally.[66]  Thus, while the Philippines may be dismayed because it is unclear when the MDT requires the United States to intervene in its defense, the United States can plausibly deny treaty obligations—to its own advantage at times.  Certainly, this may be largely a self-interested method for the United States to maintain a hands-off approach and it is perhaps not an ideal way to do business with a long-standing ally.  In addition, over time, such self-interested mechanisms may garner resentment from allies who believe the United States cares more deeply about its own domestic welfare than its legal obligations abroad.  The United States should proceed cautiously in weighing its own interests in flexibility against clearer obligations to vital allies.

Second, detractors may find that changes to the MDT could result in a substantial commitment to the Philippines in future conflicts in the South China Sea.  Particularly, those who support a more disengaged approach with allies may balk at the possibility of “coming to the rescue” of the Philippines in several different scenarios, especially as relations between Manila and Washington have cooled somewhat under the Duterte administration.  American taxpayers may rightly question how much possible commitments will cost in concrete terms, which may be problematic or hypothetical to calculate.  Conversely, it is impossible to put a price on a far more reliable guarantee for peace and stability in the Indo-Pacific; such a guarantee would be priceless.  Thus, if strategic measures under a revitalized MDT mean unquestioned boundaries for China and stronger ties with the Philippines, fiscal compromises will be much more palatable and justified.  After all, the risk of an extended and conventional armed conflict could be several times more costly than the possibility of a one-time adequate response to a gray-zone threat.

            Third, even if MDT revision negotiations are fruitful, any changes to the MDT must be ratified by the senates of the United States and the Philippines, which could pose a hurdle to implementation.[67]  If that were the case, however, the parties may instead benefit from a formal public statement to clarify American policy for interpreting the MDT as it applies to the disputed waters of the South China Sea.[68]  Any such statement could provide detailed guidance to take the MDT from the Cold War era into the twenty-first century.[69]  While it is true that this could be a viable option to modernize the treaty, it suffers from less staying power and authority than a treaty revision, which would carry a much stronger message and be more insulated from later changes in American and Philippine administrations.  Still, a public explanatory statement may be a speedy and viable back-up option if political bodies cannot agree on suitable treaty revisions, so long as any such statement is sufficiently detailed and credible.

            Finally, the United States must carefully weigh the precedent and implications of casting its lot (more than ever) with the Philippines.  After the decades-long conflicts in Iraq and Afghanistan, many American policy makers may be fearful that the Philippines will act recklessly and thereby drag the United States into a direct conflict with China or another regional competitor.  Currently, with the relatively indistinct provisions of the MDT, the risk of such adventurism appears to be low.  However, a clear mandate to defend the Philippines may risk presenting the United States with an impossible decision: escalate a minor disagreement to a major conventional war with China or potentially betray an ally and lose credibility on the global stage.

Still, diplomatic talks during and after MDT revisions will help clarify the terms of the treaty and the expectations of the parties.  Of course, the United States cannot become a guarantor of every Philippine action.  However, “China’s militarization of the Spratly [Islands] and the flood of Chinese vessels to the region” mean that “the costs of continued ambiguity from the United States far outweigh any purported benefits.”[70]  Additionally, knowing all of these concerns at the outset, greater American involvement in Philippine defense measures can be clearly conditioned on reasonable conditions precedent, guaranteeing that the United States will not be dragged into a never-ending conflict without sufficient justification, meaningful debate, and democratic consent from the citizens of both states.

VII. Conclusion

Gray-zone threats are here to stay.  Adversaries will ensure that the gray zone is the “main competitive space for as long as the United States maintains conventional overmatch, and for as long as America’s adversaries seek to pursue incompatible interests without risking war.”[71]  To fail to prepare adequately is to concede strategic defeat today.  Reassuring allies and revisiting mutual defense treaties is the surest way to leverage national security law to identify and counter gray-zone threats.  Furthermore, such measures dovetail perfectly with the prevailing “America is back” messaging from President Biden and his administration’s priority of shoring up neglected alliances as a centerpiece of foreign policy.[72]

First among the relevant legal agreements is the aging MDT with the Philippines.  With its strategic importance in the South China Sea and unique dependence on the United States, the Philippines is eager to open a meaningful dialogue with the United States about defense obligations.  If the United States does not reciprocate, it risks tacitly accepting further Chinese abuses of Philippine vessels and citizens in maritime spaces where peace should otherwise prevail.  Seizing this moment to renew talks with the Philippines over the MDT will send a clear message to China and others: gray-zone threats may fall short of war declarations, but they are nevertheless acts of aggression that will not be ignored or tolerated.

Importantly, the proposals of this paper are reproducible and scalable.  While China remains the key pacing challenge, other actors undoubtedly employ gray-zone threats to unfairly coerce other states.  In early 2022, for example, Russia threatened an invasion of Ukraine over the course of several months, amassing a sizeable buildup of troops at the border with Ukraine and eventually carrying out an armed invasion of its neighbor under the guise of peacekeeping and recognizing autonomous regions.[73]  Similar to China’s menacing actions in the South China Sea, the Russian posturing and threats leading up to the armed invasion—and even methods during the actual invasion—were very often ambiguous, belligerent, and coercive.[74]

While the United States and Ukraine have not signed a bilateral defense treaty, the parties executed a bilateral treaty on strategic partnership with provisions relating to cooperation, opposition to Russian aggression, and mutual security.[75]  Therefore, the parties could entertain treaty clarifications to address modern gray-zone threats or at the very least a public statement to reaffirm their stance against ambiguous threats.[76]  In the case of Russian aggression, much like Chinese aggression, the GRAYCON levels and criteria, paired with clear legal obligations to ally states, will convey to Russia that gray-zone maneuvers will be swiftly identified, condemned, and countered.

Opinions, conclusions, and recommendations expressed are solely those of the author and do not necessarily represent the views of the U.S. Government, the Department of Defense, or any of its components.



[1] White House, Pacific Strategy of the United States 4 (2022) (stating that the United States has a sizeable military and diplomatic presence in the region, and that the “United States has long recognized the Indo-Pacific as vital to our security and prosperity.”).

[2] Philip Kapusta, The Gray Zone, Special Warfare Magazine, at 20 (Oct. 2015), (noting that “traditional war is the paradigm, gray zone conflict is the norm”).

[3] Id. (stating that “America’s conventional military dominance and status as a global power guarantee continual challenges and incentivize competitors to oppose the United States in way designed to nullify our military advantage.”).

[4] Ashley Townshend et al., Commentary, The U.S.-Australian Alliance Needs a Strategy to Deter China’s Gray-Zone Coercion, War on the Rocks, Sep. 29, 2021, (stating that the People’s Republic of China [hereinafter China] pursues “its geostrategic ascendency in the South China Sea” through “illegal land reclamation, unopposed military construction, and the use of coastguards and fishing militias to intimidate other countries into submission.”); see also U.S. Dep’t of Defense, Fact Sheet: 2022 National Defense Strategy 1 (2022), available at (stating that China will remain “our most consequential strategic competitor and the pacing challenge for the Department [of Defense]”).

[5] White House, Interim National Security Strategic Guidance 14 (2021) (stating that the United States “will develop capabilities to better compete and deter gray zone actions”).

[6] Id.

[7] Kevin Bilms, Gray is Here to Stay: Principles from the Interim National Security Strategic Guidance on Competing in the Gray Zone, Modern War Institute, Mar. 25, 2021,

[8] See Townshend, supra note 4, at 2 (defining gray zone coercion as “the use of asymmetric tactics to achieve strategic goals without the overt use of military force”); see also Thomas Dobbs et al., Grey-Zone Activities and the ADF, The Forge, Oct. 2020, (stating that activities in the gray zone “are coercive statecraft actions short of war.  The grey-zone is a mainly non-military domain of human activity in which states use national resources to deliberately coerce other states.  States achieve grey-zone goals using multiple, apparently unrelated innocent/low attributable, mutually-supporting and synchronized statecraft techniques below the threshold of war. Grey-zone campaigns seek to exploit adversaries’ weaknesses and suppress adversaries’ response options, all the while achieving tangible national strategic aims.”).

[9] See Kapusta, supra note 2, at 22 (noting that “by definition, the gray zone is ambiguous, which results from both our own organizing principles and our adversaries’ purposeful actions.  We struggle when dealing with challenges not fitting neatly into our traditional models.”).

[10] Id. at 20 (arguing that “the United States has a well-developed vocabulary, doctrine and mental models to describe war and peace, but the numerous gray zone challenges in between defy easy categorization.”).

[11] See Kapusta, supra note 2, at 21.

[12] See Bilms, supra note 7, at 21.

[13] Id.

[14] Matt Petersen, Competition and Decision in the Gray Zone: A New National Security Strategy, Strategy Bridge, Apr. 20, 2021,

[15] Id.

[16] See Townshend, supra note 4, at 3 (stating that “unless willing nations actively stand up together, China’s gray-zone tactics will intensify and risk transforming the regional rules-based order into a Chinese sphere of influence.”).

[17] Jane Perlez, Tribunal Rejects Beijing’s Claims in South China Sea, N.Y. Times, July 12, 2016,

[18] Felix Chang, The U.S.-Philippines Mutual Defense Treaty and Philippine External Defense Forces, Foreign Pol’y Research Inst., Aug. 3, 2021,

[19] Paterno Esmaquel II, Philippines says Chinese ships near Pag-asa Island ‘illegal,’ Rappler, Apr. 4, 2019,

[20] Sean Quirk, Water Wars: Chinese Maritime Militia Disperses Amid Political Standoff with the Philippines and the United States, Lawfare, Apr. 21, 2021,

[21] Id.

[22] Id.

[23] Id.

[24] Adrien Chorn & Monica Sato, Maritime Gray Zone Tactics: The Argument for Reviewing the 1951 U.S.-Philippines Mutual Defense Treaty, CSIS, Oct. 1, 2019,

[25] Lian Buan, Palawan Fishermen Sue Duterte Gov’t for West PH Sea Neglect, Rappler, Apr. 16, 2019,

[26] See infra Sect. IV.

[27] Id.

[28] See Chang, supra note 18 (noting that the poor state of the Philippines’ external defense forces “can be attributed to a combination of factors: the end of the Cold War, Manila’s need to combat internal insurgencies, and the consistently low budgetary prioritization of its military.”).

[29] See Chang, supra note 18 (stating that “until early this year [2021], the United States had been slow to respond to Philippine appeals”).

[30] See Bilms, supra note 7 (noting that “the United States’ long-standing network of alliances and partnerships is an asymmetric advantage that America’s gray-zone competitors cannot match, and preserving that advantage is pivotal.”).

[31] See Chang, supra note 18, at 5 (noting that “the Philippines’ decades-long under-resourcing of its military had left the country utterly dependent on its mutual defense treaty with the United States for external defense.  That situation not only allowed Beijing to advance its South China Sea interests by exploiting the treaty’s ambiguities, but also limited the ability of Philippine leaders to devise effective strategies to counter Chinese assertiveness in the region.”).

[32] ANONYMOUS, THE LONGER TELEGRAM: TOWARD A NEW AMERICAN CHINA STRATEGY 10 (ATL. COUNCIL 2021) (stating that a U.S. strategy to combat China must be agreed upon in “sufficiently granular form with the United States’ major Asian and European treaty allies so that their combined critical mass (economic, military, and technological) is deployed in common defense of the US-led liberal international order”).

[33] Id.

[34] See Chorn & Sato, supra note 24, at 1.

[35] Mutual Defense Treaty between the Republic of the Philippines and the United States of America art. 4, Aug. 30, 1951, 3 U.S.T. 3947, [hereinafter MDT].

[36] Id.

[37] MDT art. 5 (“ARTICLE V. For the purpose of Article IV, an armed attack on either of the Parties is deemed to include an armed attack on the metropolitan territory of either of the Parties, or on the Island territories under its jurisdiction in the Pacific Ocean, its armed forces, public vessels or aircraft in the Pacific.”)

[38] See Chang, supra note 18 (noting that “Manila ejected the United States in a fit of nationalist pique from its bases in 1991.  And so, the Philippines—bereft of external defense forces of its own or those of the United States—left itself utterly dependent on the terms of its mutual defense treaty with the United States to deter any potential foreign aggression.”).

[39] See Chorn & Sato, supra note 24.

[40] See Chang, supra note 18, at 5 (noting that “one reason for [the modest treaty support] has been Philippine President Rodrigo Duterte’s ‘separation’ from the United States.  For most of his tenure, Duterte has sought to politically distance Manila from its alliance with Washington.”).

[41] See Chorn & Sato, supra note 24, at 1.

[42] Id.

[43] David Brunnstrom & Karen Lema, Philippines Defense Minister says U.S. Treaty Needs Comprehensive Review, Reuters, Sep. 9, 2021,

[44] Michael R. Pompeo, Remarks with Philippine Foreign Secretary Teodoro Locsin, Jr., U.S. Dep’t of State, Mar. 1, 2019, remarks/2019/03/289799.htm.

[45] Id.

[46] See Chorn & Sato, supra note 24, at 1.

[47] Id.

[48] Id.

[49] See Petersen, supra note 14, at 1.

[50] Id.

[51] Id.

[52] Eleanor Albert, The U.S.-Philippines Defense Alliance, Council on Foreign Relations, Oct. 21, 2016,

[53] See Kapusta, supra note 2, at 22.

[54] See, e.g., U.S. Army Fort Gordon, Force Protection Condition,, last visited Feb. 27, 2022.

[55] See Chang, supra note 18 (noting that the poor state of the Philippines’ external defense forces “can be attributed to a combination of factors: the end of the Cold War, Manila’s need to combat internal insurgencies, and the consistently low budgetary prioritization of its military.”).

[56] See Chang, supra note 18, at 1.

[57] Id.

[58] Convention on the Law of the Sea art. 56, Dec. 10, 1982, 1833 U.N.T.S. 397,

[59] Gregory Poling & Eric Sayers, Time to Make Good on the U.S.-Philippine Alliance, War on the Rocks, Jan. 21, 2019,

[60] See Chang, supra note 18, at 5.

[61] Id.

[62] Id.

[63] Id.

[64] See Townshend, supra note 4, at 2 (stating that China pursues “its geostrategic ascendency in the South China Sea” through “illegal land reclamation, unopposed military construction, and the use of coastguards and fishing militias to intimidate other countries into submission.”).

[65] Id.

[66] See Chorn & Sato, supra note 24, at 1 (stating that “like most conventional defense treaties and standards, the MDT is not clear about the increasingly common unconventional gray zone threats that skirt the definition of war to avoid prompting a kinetic response.”).

[67] See Poling & Sayers, supra note 59.

[68] Id.

[69] Id.

[70] See Poling & Sayers, supra note 59.

[71] See Bilms, supra note 7, at 1.

[72] White House, Remarks by President Biden on America’s Place in the World, Feb. 4, 2021,

[73] Michael Schwirtz, Russian Troops in Final Stages of Readiness Add to Worries for Ukraine, N.Y. Times, Feb. 4, 2022, (stating that portions of the Russian “army have reached full combat strength and appear to be in the final stages of readiness for military action should the Kremlin order it.”); see also Katie Rogers & Andrew E. Kramer, White House Warns Russian Invasion of Ukraine Could Happen at Any Time, N.Y. Times, Feb. 11, 2022,

[74] See Schwirtz, supra note 73 (stating that “the Kremlin’s ultimate intentions remained unclear” and that American officials “say that President Vladimir V. Putin of Russia has yet to decide whether to attack.”).

[75] See U.S. Dep’t of State, U.S.-Ukraine Charter on Strategic Partnership 2 (2021) (expressly stating that the “United States and Ukraine intend to continue a range of substantive measures to prevent external direct and hybrid aggression against Ukraine and hold Russia accountable for such aggression and violations of international law, including the seizure and attempted annexation of Crimea and the Russia-led armed conflict in parts of the Donetsk and Luhansk regions of Ukraine, as well as its continuing malign behavior.”).

[76] See supra Sect. VI (stating that “a public explanatory statement may be a speedy and viable Plan B option if political bodies cannot agree on suitable treaty revisions, so long as the statement is sufficiently detailed and credible.”).

Categories: Japan

About the Author(s)

Captain Matthew H. Ormsbee is a commissioned officer in the United States Air Force Judge Advocate General’s Corps, currently stationed at Misawa Air Base, Japan; J.D., Benjamin N. Cardozo School of Law; B.A., Hendrix College.