This month, President Trump gave a green light to Turkey to move against the Kurdish People’s Protection Units (YPG) that had fought alongside the United States in northeast Syria against the Islamic State. The move sparked bipartisan outrage in Washington.
Many critics worry that the United States’ credibility as an ally is on the line. But our research exploring the impact of military interventions on alliance credibility suggests these fears are potentially overblown.
If withdrawal from Syria were to be handled properly, America’s credibility as an ally could weather the storm and might even emerge stronger. What really matters is how the Trump administration has gone about managing — or, rather, mismanaging — this shift in U.S. foreign policy.
Those who chase credibility end up with none
Allies live in constant fear of abandonment. Smaller allies often worry that when push comes to shove, their great-power patron may not come to their aid. They understand that allies share some, but not all, interests and that the alliance “halo” is often quite limited. With good reason, the Kurds care less for Trump’s fulsome tweets than for his deeds.
How can nervous allies be reassured? During the Cold War, scholars and policymakers argued that the United States could bolster its credibility with adversaries and allies by consistently embracing hard-line policies and displaying strength. Limited military interventions, especially in far-off locales in defense of secondary priorities, would be particularly effective in reassuring nervous allies.
If a major power was willing to expend significant resources in places of trivial value, it would surely honor its commitments to allies in locations of far greater strategic interest. This logic led, among others, to the U.S. intervention in Vietnam and the Soviet War in Afghanistan — now generally seen as tragedies for all involved.
Such arguments did not die with the end of the Cold War. President Barack Obama was pilloried by critics across the political spectrum in 2013 when he shied away from launching a bombing raid in response to the Syrian government’s use of chemical weapons. They subsequently accused him of thereby emboldening the Russians — contributing in early 2014 to Russia’s annexation of Crimea and its covert intervention in Ukraine and in fall 2015 to its overt intervention in Syria. His about-face, they contended, had frightened traditional regional allies, notably the Israelis and Saudis, who began to consider other patrons and arms suppliers. Trump’s sudden announcement, for the second time, that U.S. forces would be withdrawn from Syria has reportedly worried U.S. allies even beyond the Middle East.
Yet this logic is a recipe for never-ending interventions and ever-expanding commitments, which will eventually undermine alliance credibility. If states can never walk back existing commitments, they will be stretched so thin that others must doubt their will and capacity to fulfill their core alliance commitments. Credibility is a greedy master that no state can unthinkingly serve. Those who chase credibility as a means to national security — by embracing uncompromising policies, steadfastly upholding all commitments, and refusing to retrench — find themselves without either credibility or security.
Pulling back need not undermine alliances.
The Vietnam War was precisely the kind of high-cost intervention that should have powerfully signaled U.S. resolve and reassured its allies around the world. In fact, we find, the war made America’s allies outside the region more nervous than ever that the United States might renege on its commitments. When the United States finally pulled out of Vietnam, withdrawing with little honor, its allies cheered.
Our research suggests that, if handled properly, withdrawals from existing commitments can hearten allies. However, this requires publicly drawing clear distinctions between core and peripheral interests, employing a considered policy review process, and working to minimize negative policy externalities — none of which Trump did in suddenly announcing, via tweet, on Oct. 7 that “it is time for us to get out of these ridiculous Endless Wars, many of them tribal, and bring our soldiers home …” The muddle of public statements from U.S. officials that followed over the next two weeks only compounded the issue.
If the Trump administration had made a consistent and cogent case that intervention in Syria was no longer in the national interest, then other allies might not have been rattled. But, in fact, U.S. officials had long suggested that the battle against the Islamic State was a vital U.S. interest, and they had — contrary to the president — argued in recent weeks that the Islamic State had by no means been thoroughly defeated.
It is the mismanagement of the Syria pullout that is weakening U.S. alliances
When states doubt their allies, they prepare for future abandonment. They explore other avenues to security by increasing military spending or seeking new partners or even suing for peace with former adversaries. Our research into the Vietnam era found that, as America’s European allies grew increasingly skeptical of U.S. capability and will in the 1960s, they hedged their bets in all these ways.
The Syria pullout will invite such hedging today — not because it has happened, but because of how it has been (mis)managed. That the Kurds immediately brokered an alliance with the Syrian government surprised no one. That the Israelis are now thinking twice about putting their trust in “Trump, prince of Jerusalem,” is only slightly more surprising. Other allies, from Europe to Asia, are also expressing concern.
Trump’s recent decision to send U.S. troops back to Syria to “secure the oil” can hardly have been reassuring. However, the apoplectic response among politicians and pundits in the U.S. foreign policy establishment misleadingly implies that any U.S. pullback is not only a “betrayal” of its allies, but is strategically unwise to boot.
Withdrawing from “Endless Wars” is not, in and of itself, a problem — either morally or, we argue, strategically. Withdrawing haphazardly and impulsively is what leads to crises in alliance credibility.
Ronald R. Krebs is a professor in the liberal arts and professor of political science at the University of Minnesota.
Jennifer Spindel is an assistant professor of international security at the University of Oklahoma and a fellow at the Dickey Center at Dartmouth.