How to Respond to Gray Zone Aggression in the Indo-Pacific

As any observer of the Indo-Pacific knows, changes have been afoot in recent years. Lasers temporarily blind reconnaissance satellites. Man-made islands rise atop reefs as newly minted outposts of alleged Chinese sovereign territory. “Emergency defensive measures” are threatened against aircraft that would fly through international airspace near China without obeying expansive Chinese air controls. News reports over recent years have documented these and other aggressive Chinese “gray zone” activities, which are meant to gradually achieve goals China would not be expected to attain through direct means or other international rules-based processes.

Generally speaking, gray zone activities are activities on the international relations continuum that are unfriendly and adverse to other nations but that do not cross the threshold of armed conflict. Depending on the specific gray zone activity, the action may directly violate the offending nation’s international obligations, or it may simply exploit weaknesses and vagaries in international law or international resolve. Gray zone activities are characterized by the use of an incrementalist approach to obtain geopolitical ambitions, slowly executing contentious and often internationally wrongful actions to ultimately obtain an end state that would have been resolutely opposed had it been clearly pursued in the beginning. Gray zone activities create, embrace, and exploit a murky space between war and peace. In a European context, gray zone activities are those that begin with shadowy “little green men” appearing in Ukraine and lead to the Russian annexation of Crimea.

While China and some other nations operate nimbly and effectively in this gray zone, the United States and its allies and partners have struggled to find ways to effectively respond. If the United States and others are to push back against malign gray zone activity while promoting and maintaining a commitment to an international rules-based order, they must rethink how, whether, and when they implement the international law concept known as countermeasures.

Countermeasures: What Are They?

The elevator speech description of countermeasures is that they are an international law mechanism that allows one nation to respond to another nation’s internationally wrongful acts with a move that would itself be internationally wrongful were it not for the aggressor nation’s initial wrongdoing. In other words, countermeasures let nations fight unlawful acts with tailored, and otherwise unlawful, acts of their own. Although classic countermeasures are thought of in what can be described as a non-traditional security context (the leading International Court of Justice opinion on countermeasures concerns violations of a treaty on dams and water use, for instance), there is no requirement that they be so contained. In fact, much recent scholarship has focused on the use of countermeasures as a response to state-sponsored cyberattacks.

Although countermeasures are powerful in that they allow a nation to take otherwise prohibited actions against another nation, they are governed by some restrictions. Foremost, countermeasures may not involve the use of force. This distinction should generally have little impact in the fight against malign gray zone activities, however, since gray zone activities by their nature take place below the level of armed conflict. Additionally, countermeasures must be designed and executed to bring the offending nation back to compliance with international norms and as a general rule must cease when the offending behavior stops. That again is not a significant burden in fighting gray zone activities, since the goal of countermeasures would be not to punish, but to stop the malign gray zone activity and return the parties to the position they were in before the wrongful gray zone activity was initiated. Countermeasures must also be proportionate to the injury suffered, though so many factors can be taken into account in the analysis of one’s national injury that the proportionality requirement should not create a notable hinderance to crafting effective countermeasures.

Why Countermeasures?

Countermeasures are especially suited for gray zone competition because they place otherwise unlawful acts in the toolboxes of the U.S., allies, and partners, and they need not be limited to the same military domain or even the same instrument of national power as the precipitating act. For instance, the wrongful lazing of a reconnaissance satellite’s sensors might be met with an otherwise-wrongful cyberattack against a power station that supports the offending nation’s naval logistics hub; incursions into national airspace might be met with the injured nation temporarily refusing to uphold unrelated but legally binding treaty obligations toward the offending nation. This robust view means countermeasures are agnostic to domain, geography, and instrument of national power. An aggressor nation’s repeated internationally wrongful lazing of satellites in outer space can now place that nation’s economic system instruments at proportional risk.

Furthermore, countermeasures are important because they promote a rules-based order over raw power. Countermeasures allow the United States and its allies and partners to creatively design and employ potent responses against unlawful actions and to do so while staying within and actively promoting the rules-based international order. They provide a way to not just practice rules-based responses, but to show that they can be effective against brazen and internationally wrongful power plays.

Countermeasures also legitimize and grant access to tools that allow injured nations to at least partially circumvent the question of how to characterize what China is doing. Instead of asking whether the malign behavior in question constitutes a use of force (or an armed attack, which is generally accepted as a higher standard whose interpretation has some disagreement among the U.S., allies, and partners), the only question is whether the malign activity is internationally wrongful. If the answer to that question is yes, countermeasures may be used.

Practical Considerations

The Atlantic Council’s recent strategy paper, “Seizing the Advantage: A Vision for the Next US National Defense Strategy,” highlights a need for interagency cooperation in executing what the paper describes as hybrid warfare using all instruments of national power across the full spectrum of international competition. In the U.S., a successful and vigorous use of countermeasures will necessitate and can consequently help drive interagency cooperation, and one can expect a similar situation for U.S. allies and partners.

Since countermeasures are the execution of a normally prohibited action or omission by one nation against another nation, it is not something that can or should be done unilaterally by one government agency. As part of the interagency coordination, there will need to be a determination that the injured government does in fact consider the precipitating act to be internationally wrongful and wants to make such an assertion. Similarly, there should be a standing interagency mechanism to identify and assess internationally wrongful gray zone activities to target, and to identify and develop countermeasure options across domains and instruments of national power.

In some instances, especially those with more complex strategic implications, this interagency coordination may be a slower process. In other circumstances, such as where a reconnaissance satellite is being repeatedly blinded by a laser during escalated tension, in violation of international law’s protection of the free use of outer space, an interagency countermeasures cell could coordinate and execute “urgent countermeasures,” which may be permitted with fewer preconditions in order to rapidly protect a nation’s rights. Similar multilateral arrangements may also be helpful to coordinate with allies and partners in determining appropriate countermeasures responses, in part since a clear gray zone “victim nation” will not always be obvious.

Although countermeasures offer an important tool in fighting malign gray zone activities, they are not a panacea. As previously noted, they may only be invoked if the aggressor state’s activity is internationally wrongful. While gray zone activity is often internationally wrongful, it isn’t always. Also, some thought must be given on a case-by-case basis to proportionality and how long a countermeasure may continue, though the range of factors that can be incorporated into those determinations leave room for flexible execution in coordination with relevant government players. Other requirements, such as the need to continue to obey peremptory norms like respect for human rights, must be followed but will provide little practical impediment.

Countering Gray Zone Aggression

Thus far, the gray zone strategy embraced by China and other actors who would thwart a rules-based international order has been fruitful. If other nations in the Indo-Pacific are to counter malign gray zone activities, they must do so intentionally and holistically. As former Secretary of Defense Chuck Hagel noted in his forward to the Atlantic Council strategy paper, “A more closely coordinated approach between nations and across the whole of government is needed to deter, defend, and shape the strategic environment, if the US security and defense apparatus is to be nimble enough to deal with the ‘gray zone’ warfare that resides just below the threshold of armed conflict.”

Hagel is right, and countermeasures can be a robust tool that the U.S. and its allies and partners should embrace if they are going successfully counter gray zone activities that undermine the international rules-based order.