Great-power competition may conjure up images of war in Europe or the Pacific, and U.S. defense planners are rightly preparing for head-on collisions. But the Cold War and the Global War on Terror suggest that the future of conflict will more likely be limited to indirect skirmishes at the fringes of great-power influence. To succeed in this environment, the United States should plan for proxy warfare.
So we looked at the U.S. experience with conflicts in which it supported one side without playing a major direct role in the fight. Cold War examples include the Hmong army in Laos, the Afghan mujahideen, and the Nicaraguan contras. We also examined the more recent Anbar Awakening in Iraq, the African Union Mission in Somalia (AMISOM), and the Syrian Democratic Forces, or SDF. We gleaned several key lessons, which we have laid out in “The Cheapest Insurance in the World? The United States and Proxy Warfare,” a new report from CNA.
In each case we studied, proxies achieved some U.S. goals. The Sons of Iraq in Al Anbar province suppressed insurgent activity, reducing U.S. casualties. The Hmong tied up North Vietnamese divisions. AMISOM has disrupted — though not defeated — al-Shabaab and improved security in Somalia. The mujahideen got the job done in Afghanistan, harassing Soviet forces until Moscow withdrew. And the Kurdish-dominated SDF took and held Syrian territory from the Islamic State of Iraq and Syria, or ISIS.
And yet planners must weigh near-term objectives against possible collateral effects. The United States has endured blowback from providing training and arms to the mujahideen. Support to the SDF has created a diplomatic headache with Turkey, whose ties to its NATO allies were already under strain.
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Second, proxies still require a U.S. footprint. Though the political and financial costs can be far less than those of direct military intervention — not to mention the risks to tens of thousands of U.S. ground forces — success depends upon some measure of U.S. involvement. For example, U.S. special operations forces advise, assist, and accompany AMISOM units during operations in Somalia, and U.S. aircraft provide strikes when these patrols come under assault by al-Shabaab. These sponsor forces operate in harm’s way, and the logistical tail to support U.S. forces embedded with partner forces can be complex.
Third, efforts to use proxies should be confined to irregular warfare. In great power conflict, or facing any well-trained state military, it is a mistake to employ a proxy force in a conventional role. In Laos, the Hmong launched a successful guerrilla war against the North Vietnamese army and its local communist ally, the Pathet Lao. But once emboldened by U.S. air power, the Hmong went on to fight conventionally against the North Vietnamese, and subsequently suffered devastating losses.
Fourth, “secret” wars don’t stay secret. During the Cold War, U.S. leaders mounted proxy wars to mask U.S. involvement in various regions around the globe. But American backing for the Hmong, mujahideen, and Contras became public knowledge. That was three decades ago. Given the ubiquity of mobile phones and social media, it is difficult to imagine any large-scale proxy war staying secret.
Fifth, proxies are likely to commit human rights abuses, so U.S. policymakers and military planners must to consider how to respond. The contras indiscriminately attacked Nicaraguan civilians, and reports of sexual assault in Somalia have dogged AMISOM forces. Abuse committed by U.S. proxies becomes America’s moral baggage. Even worse, the targeted population may conclude the United States is behind these violations. The Kurdish contingent of the SDF allegedly threatened Arabs with U.S. airstrikes as the Kurds moved to displace the local population from areas the SDF captured.
Sixth, local legitimacy matters. Proxies that lack legitimacy appear to have less operational effectiveness. One reason for the success of the Anbar Awakening was that it provided the tribes of Iraq’s Anbar province with a parallel governing structure they viewed as more legitimate than rule from Baghdad. The less-successful Contras, in contrast, couldn’t gain legitimacy as Nicaragua’s “liberators” in the eyes of their compatriots.
Finally, proxy warfare is transactional. The day after President Donald Trump announced his decision to pull all U.S. troops out of Syria — in effect abandoning the SDF — Defense Secretary James Mattis argued in his resignation letter for “maintaining strong alliances and showing respect to those allies.” But proxy warfare is a transactional relationship between sponsor and sponsored, not a long-term alliance. Proxies are meant to be cut loose after they serve their purpose.
This may seem fickle, but knowing when to walk away can save the sponsor from mission creep. One can argue that it is too soon to withdraw from Syria. But the U.S. government was always clear that it would abandon the SDF eventually. U.S. Special Envoy James Jeffrey best explained the transactional nature of proxy warfare the day before President Trump made his withdrawal announcement: “We do not have permanent relationships with substate entities. That is not the policy of this administration and has not been the policy of other administrations.”
Proxies have agency, too. These groups gamble that the relationship, no matter how short-lived, will give them the weapons and other support needed in the immediate term, as well as training and assistance that could serve their own interests after the sponsorship ends.
To maximize the chances for success and minimize risks, our study recommends a number of “rules of thumb” for policymakers considering the use of proxies. These include setting limited, reasonable objectives and recognizing that proxies may take longer to achieve these objectives than direct U.S. military intervention. Planners should also consider collateral effects of support to proxies.
Most important, proxies should not be treated as long-term partners with unquestioning support. Proxies that believe they have full support of their sponsor — no matter how they act — are more likely to act recklessly. When the conflict is over or proxies are no longer acting in U.S. interests, the United States must be prepared to walk away.
The views expressed here are those of the authors and do not necessarily reflect those of CNA or any of its sponsors.