Writing in the Atlantic late last month, journalist George Packer posited a “new theory of American power,” a liberal internationalism that accounted for a “recognition of limits” for US foreign policy. Packer summed up this strategy toward the end of his essay: “Align US policy with the universal desire for freedom, but maintain a keen sense of unintended consequences and no illusions of easy success.”

This was both a challenge and a promise to Americans wanting to move on from the “war on terror”: don’t forget the war on terror’s failures — and reject its methods (torture and rendition) — but maintain a vision of global “freedom” flourishing through military power. The war in Ukraine, Packer argued, had killed the (now fleeting) popularity of “restraint” — the idea that the United States should scale back its international commitments, cut or remake the military budget to reflect a reduced role for the United States in the world, and give up on a strategy of what political scientist Barry Posen has called “liberal hegemony”

As one would imagine, Packer’s essay caused a stir, if not a visceral loathing, among restrainers (the term du jour for anti-interventionists). But as historian Samuel Moyn tweeted, Packer’s essay — while gilding liberal internationalism for a rehabilitation of American primacy — reflected the reality that the old order cannot return after the war on terror, “that a militarism-first option of liberal warmongers can’t simply be revived.”

Moreover, military options that characterized the war on terror are currently off the table: preemptive invasion — and occupation — of sovereign nations, nation-building in the Middle East, unipolar dominance by the United States, etc. Due in part to the work of journalists like Azmat Khan, drone strikes have decreased dramatically during the presidency of Joe Biden. Elements of restraint are also evident in the Biden administration’s policy toward Ukraine. Ostensibly motivated by fear of nuclear escalation, Biden has rejected “New Cold War” hawks’ calls for a no-fly zone, sending certain high-tech weapons to Ukraine, and the prospect of a direct US intervention in Ukraine. In dealing with great or failed states, Biden is operating in the shadow of the US inability to remake the world, even as many national security figures wish this wasn’t so.

Alone or in their aggregate, these new realities do not comprise a foreign policy of restraint. Restraint must be instrumentalized for a new US foreign policy — it is not the end in and of itself. As the war in Ukraine continues with no foreseeable end in sight, it provides restrainers with the means to envision and implement a postwar vision for the world. Restrainers must be critical of efforts to expand US power in the short term (for instance, a blank check to the Pentagon to fight the war), but must also look to build an affirmative vision that relies upon international collaboration to reprioritize national security threats (around issues such as climate change, migration and refugee policy, poverty, and global health); deter imperial adventures by great powers; and demilitarize the landscape of foreign policy options once the war ends.

But first, what is restraint? Restrainers are often forced to defend their positions against liberal internationalists. The supposed clarity of liberal internationalism — support for global liberty and freedom achieved through military force and economic might, and buttressed by the inherent exceptionalism of the United States as a democratic superpower — is juxtaposed with the supposed murkiness of “restraint” as a category or term. Restraint can be defined in many ways, but as a heuristic, it is often reduced to the idea of pulling back from the world stage — and is pilloried as a synonym for “isolationism,” an even more loaded term.

In addition to the capaciousness of restraint, other factors hobble its proponents. Restraint has yet to be tested as a basis for US national security. Restraint is not codified in institutions of foreign-policy making in the United States — quite the contrary. Restrainers also disagree on the ends of restraint. Some restrainers are nationalists and fiscal hawks who believe that monies spent abroad fighting monsters, to paraphrase John Quincy Adams, impair US business interests and free trade, and raise debts and tax rates. These restrainers are less concerned with matters of international justice. Other restrainers are self-described realists focused on “offshore balancing,” who seek spheres of influence akin to the Congress of Vienna following the Napoleonic Wars.

Progressive or left-wing restrainers, like myself, believe in a demilitarized world determined by international cooperation on issues outside of military competition (poverty, health, climate, for example), that can limit conflagrations between great and small powers. Some progressive restrainers have faith in cooperation among member states of the United Nations through proposed forums like a “Summit of the Future,” which they believe can spearhead international comity.

These divides within the restraint camp are real, but have too often been hyperbolized, deployed to create caricatures or straw men in service of jingoism. Liberal internationalism struggles with its own contradictions — for example, relying on undemocratic means (military force) to create ostensibly more democratic ends (liberal democratic societies) — but these fissures have not hamstrung the salience of its policies.

This is because liberal internationalism became normative, even naturalized among foreign policy elites during World War II and into the Cold War. As historian Stephen Wertheim has written, US foreign-policy makers made a conscious choice to pursue primacy during World War II — and the Allied victory allowed them to sell their vision to the public. Except for brief moments, such as in the immediate postwar period and the late 1960s and early 1970s, restrainers in US foreign policy have occupied the minority position. The totalizing fear of Soviet dominance or Islamic terrorism conjured unfulfilled panics about the demise of freedom and democracy. Amid an unstable world and an era of permanent national emergency, the use of military force to prevent illiberalism and ensure American interests became an all too convenient, and easily available, option.

But restraint will not thrive simply as the critique or opposition to liberal hegemony. Restraint cannot be reactive and defensive, seeking out assorted hawks to lampoon online or in print. That is too easy. Restraint must also not be the corollary to military withdrawal following imperial misadventure — its resonance cannot lie waiting for America to make mistakes abroad, for empire’s excesses to be revealed. Such was the case with the withdrawal of United States from Vietnam in the 1970s, or Afghanistan in 2021.

As Emma Ashford has argued, restrainers must be forward-looking. They must build an alternative strategy to liberal internationalism that is codified around principles of universal equity; freedom from foreign interference, coercion, and invasion; global collaboration across wealthy and poor nations; and international institutions that provide checks and balances on military spending. In a time of multiple serious dangers — imperial war in Ukraine, autocrats flourishing in the Global North and Global South, the catastrophe of climate change, the unattended failures of the global response to COVID-19 — the temptation will be to adopt familiar paradigms that harken back to the Cold War.

This appears to be what is happening now, with the rush to subsume all global issues under the framework of “great-power competition.” Restrainers must acknowledge this reality while mitigating its outcomes. They can highlight the multiple paths to achieve global cooperation, to prevent future Ukraine-like invasions, and to avoid turning Ukraine into a “Munich” — an analogy and justification for preemptive invasions of nefarious regimes under a new US administration.

If these suggestions seem utopian, I offer history as perspective. “One-world” cooperative, internationalist visions were commonplace in the early aftermath of World War II. Ideas for sharing atomic secrets with the Soviet Union under the 1946 Acheson-Lilienthal report, or for a world federalist movement that reformed the United Nations to make the great powers more accountable to colonized nations, were discussed but never realized. Total war and atomic weapons broke open the realm of the possible in conducting world affairs. Given the transformative effects of the war in Ukraine on global issues (on trade, oil, transatlantic relations), the conflict could create a similar moment in which new paths become possible.

It is true that the political climate in the United States has stifled a discussion about the future, of what is acceptable discourse on war. The shock of the invasion, and the durability of Ukrainian resistance to the Russian military, propelled public support for the war. An honest conversation about a long-term commitment to Ukraine got lost in the process. The hand-wringing and fallout from the Congressional Progressive Caucus letter to President Biden, which called for a relatively anodyne series of policies that largely echoed the administration’s line on Ukraine, further testified to the caliber of debate about the war’s future. These factors have no doubt stymied restrainers’ agenda.

But restrainers are a more visible, organized bloc than at any time in recent memory. Restrainers have homes in academia and at various think tanks, not just the Quincy Institute for Responsible Statecraft, but also the Carnegie Endowment for International Peace and the Stimson Center. The fallout from the war on terror is still fresh in Americans’ minds, and when polled, Americans overall favor foreign policy retrenchment. Combined with the steps not taken by Biden to escalate the war, this atmosphere proves to be favorable to restraint.

And at this point in the Ukraine war, two interrelated scenarios seem likely. The first is that the conflict will grind on as a war of attrition. The war threatens to become a yearslong stalemate that will tragically see thousands more Ukrainians killed and Ukrainian infrastructure further decimated. The current US strategy will be the same months from now, and the United States will continue to increase security assistance to Ukraine, even under a Republican-controlled House of Representatives.

The second is that this war, as most wars do, will likely end by diplomatic accord, by some international agreement. A march to Moscow to stop the Russian war machine (akin to World War II), or a reluctant capitulation by Vladimir Putin to Volodymyr Zelensky (à la Robert Lee to Ulysses Grant at Appomattox), seem unlikely in both historical and contemporary terms. More possible is that the Russian regime destabilizes due to changes to global politics and internal dynamics (such as those that propelled the Soviet exit from Afghanistan in 1989), or the Russian Federation decides its losses are enough — perhaps under a new Russian president — and looks to exit Ukraine by achieving “peace with honor,” like the United States did in Vietnam in 1973.

But as the war continues, and the endgame draws closer to reality, the tyranny of possibilities for what the war holds in the short term will diminish, as will claims that the restrainers seek to deprioritize or decenter Ukraine from the state of global affairs. This war too shall pass.

And at some point, the question will inevitably be asked: What comes next? Restrainers should have an answer to this. Paeans to multipolarity will not create the institutions that prevent imperial wars, nor will ideas for a Marshall Plan for Ukraine. For these frameworks are inherently nationalist in scope, reifying the authority of great-power conflict to restrict foreign policy decision-making and place the interests of the few ahead of the many. There is an opening for restrainers to offer something new. It cannot be the “one-world vision” of decades ago, but we cannot allow stability to rest in the hands of great-power deterrence, in the hopes that Global South nations like India will align with the United States over Russia because of a pull toward democratic “values.”

Just as presidential administrations create their own National Security Strategy (NSS), restrainers — particularly those in the progressive, or left-wing, camp — must come together as a group (in a conference, or similar forum) to offer their own NSS on a semi-regular basis, perhaps every four to eight years. This would give restrainers (supported by prominent think tanks) a universal document to reference when confronted with the question of “What is restraint?” or “What should be our policy toward Ukraine?” There are hundreds of public restrainers, and creating a working group, at minimum, is a feasible first step to creating a tangible strategy.

Restrainers must therefore take Packer’s essay — and future ones like it — as a call to arms, a genuine opportunity to formulate what a “new restraint order” would look like. Now is the time for restrainers to offer a strategy that replaces “great-power competition” in favor of one that unites nations on common terms of international importance. If the war in Ukraine is indeed a paradigm shifting event, it should not be wasted.