Executive Summary

On Sunday, October 6, 2019, U.S. Special Operations Forces were on patrol with the Syrian Democratic Forces (SDF), the mostly Kurdish militia that has been, since 2015, a key ally in the fight against the Islamic State (IS). That same day, Turkey’s President Recep Tayyip Erdogan convinced U.S. President Donald Trump over the phone that Turkey could stabilize northeastern Syria and address the issues keeping approximately 1,000 U.S. forces in the country.¹ Later that same day, the White House issued a press release explaining that the U.S. forces “will no longer be in the immediate area.”²

On the ground in Syria the next morning, October 7, 2019, SDF commander Khalil Khalfo explained that, “at six [a.m.], we got a message telling us they’re leaving. That was it.”³ At 6:30 a.m., U.S. forces withdrew from an area that included four key border outposts inside a zone that U.S. special forces had been jointly securing with Turkish troops.⁴

The decision to withdraw American forces from northeastern Syria triggered a Turkish incursion into the area: Operation Spring of Peace. This operation, which began on October 9, 2019, and continues as of this writing, intends to push Syrian Kurdish militants from the border with Turkey and repopulate the towns in these areas with Syrian Arab refugees. To accomplish this mission, Turkey’s armed forces are using in-country allies drawn from the Syrian National Army (SNA), a militia made up of about thirty Syrian nationalist and religious factions. The Turkish-led offensive opened new fault lines in the Syrian conflict, ones that fundamentalist insurgent groups like IS will exploit to endure despite all efforts to defeat them.

The American relationship with the SDF was, in many ways, a model of effective American proxy warfare.⁵ The United States had learned some hard lessons on how to operate in the Syrian battlespace from 2011-14, and had applied them to its partnership with the SDF. The strategic purpose of U.S. cooperation with the SDF was clear at the outset: destroy the Islamic State’s existence as a territorial entity. These lessons and a more clearly defined strategy meant that the United States was far better equipped to develop a partner force capable of carrying out its mission. And because U.S. forces were deployed to the region and embedded with the SDF, they were much more effective at managing the complex relationship.

Yet, President Trump’s decision to withdraw U.S. forces, although rash, is not a symptom we can dismiss as an eccentricity of the Trump presidency. The reason this paper is entitled “The Tweet of Damocles” is not solely because of President Trump. Rather, it is because America’s foreign policy can change quickly, and because any proxy warfare campaign is so fragile and complex that it can unravel quickly. In the case of the U.S.-led fight against IS, we have seen an effective proxy warfare campaign undone with a phone call and a few tweets. However unusual the process, the fact that an intricate strategy of engaging proxies to fight in foreign wars can be so quickly undone is more likely to be the rule than the exception. This paper will describe broader challenges associated with the United States’ approach to proxy warfare and the limitations of even the most successful models of American proxy warfare when undertaken.

Key Findings

• The United States’ effort to back Syrian rebels from 2011-2014 was a failure. But the ways it failed are instructive for developing a more effective proxy warfare campaign. This period offers three lessons for future campaigns.
  • Sponsors must assess whether they have clear, consistent, and achievable strategic objectives for the proxy relationship.
  • Sponsors must assess whether their chosen proxies are capable of taking and governing territory.
  • Sponsors must assess the extent to which they can mitigate three core problems of managing proxies: information deficiencies, principal-agent challenges, and international coordination problems.
• U.S. support to the SDF as part of the counter-IS war represents a largely successful model of proxy warfare because it applied the three lessons above. However, its eventual failure illustrates the unavoidable downside risk of proxy warfare: it is complex, unpredictable, and subject to the whims of shifting American foreign policy-making.
  • The United States maintained a relatively clear strategic goal throughout the counter-IS campaign: to degrade and destroy IS as a territorial entity. The campaign succeeded in that objective with IS’s loss of its last territories in Iraq and Syria.
  • The SDF was capable of taking territory from IS and governing it over time, providing a framework for a lasting military and political solution.
  • By deploying troops and diplomats to northeastern Syria, the United States limited the information deficiencies, principal-agent issues, and international coordination challenges that undermined its earlier efforts.
  • However, an inability to determine whether the United States was seeking merely to disrupt IS or aiming to fundamentally change the Syrian conflict created the conditions for the October crisis in the relationship once the initial objective was achieved.
• Proxy warfare is more often resourced to disrupt rather than to defeat an adversary. Proxy warfare campaigns often cannot address the complex social forces that gave rise to a terrorist group or fundamentally shift the political dimensions of a civil conflict.
• The Turkish proxy campaign in northeastern Syria will likely face two challenges: 1) principal-agent problems in trying to manage Turkey’s Syrian proxy force; and 2) issues in devolving governing authority over northeastern Syria to those proxies, a task for which they are ill-suited.
• Fundamentalist insurgents are better equipped than most proxies to survive internationalized conflicts in the Middle East. They have learned to avoid the pitfalls of proxy relationships and focus on developing effective local power.
• The United States will continue to wage war by proxy in the Middle East. However, American proxy warfare will fail to achieve objectives beyond disruption of an adversary for two principal reasons:
  • American proxy strategy is inherently limited by the complexity of the mission and the ease with which that mission can be dismantled by even minor policy shifts from decision-makers.
  • Using proxies as a force to change the social or political dimensions of a country’s conflict would require greater commitment to the proxy relationship (i.e., involving more substantial force and political backing) than the American public is likely to support in the Middle East for the foreseeable future.