Conclusion

Over the summer of 2014, the Obama administration returned the United States to war in Iraq, then extending the war into Syria. The decision, justified in part on preventive war logic, has helped fuel America’s endless wars. Yet there is a strong case that the war on ISIS was justified. The war liberated almost 8 million people from a brutal terrorist regime that, among other atrocities, instituted slavery and committed genocide.¹ ISIS had also demonstrated a capability to direct attacks in Europe that it incontrovertibly manifested with attacks in Paris in 2015 and in Brussels in 2016. The war likely diminished ISIS's capability to conduct such attacks.

Even restraint-oriented realist critics of the counter-ISIS war view it today as success, albeit grudgingly and while noting that it is a limited one.² Others have celebrated the campaign more explicitly, calling it a “mission that succeeded with a light footprint and relatively low costs.”³ Such a conclusion should not be dismissed, and ISIS's demise is certainly, as the realist scholar Stephen Walt puts it, “welcome news.”⁴

Yet the rhetoric of success is reliant on an error of analysis. It separates the counter-ISIS war from the multi-decade history of American warfare in Iraq. It also calculates the cost of the war while the war remains ongoing. The costs look very different if the counter-ISIS war is seen as simply the latest phase of a longer war in Iraq. The costs will also look very different if the United States finds itself continuing to fight in Syria and Iraq, with its forces grinding against other major powers’ forces, let alone if that grinding escalates to a larger war.

Rhetoric of success also focuses on some war aims—most notably those tied to regional security rationales—while obscuring evaluation of the preventive war logic’s justification and its lack of support. It is possible for certain justifications for war to be reasonable and successfully implemented while others are not supportable. For this reason, it is essential to look at preventive war logic, and other rationales, on their own merits and not allow analysis to shift between objectives when analyzing success.⁵ Even if the United States determines that war was and is necessary for regional security interests, publicly framing it as a strategy to prevent future attacks is counterproductive as it discourages strategic thinking about tradeoffs, raises questions about the commitment of the United States to the effort, and raises the prospect of sudden, unplanned withdrawals if policymakers lose trust in military and other security leaders pitching one objective and strategy while pursuing another.⁶ Trump’s unplanned withdrawal from northeastern Syria starkly illustrates what can happen when the president and public lose that trust.

Some politicians have embraced criticisms of the war in Syria or at least its continuation. It has become popular among politicians across the political spectrum to call for an end to endless war. President Trump even framed his withdrawal from northeastern Syria in terms of ending endless war. The greater awareness of the costs and risks of endless war should be celebrated. Yet, those who seek to end America’s endless wars will need to do more. Consistently, candidates maintain a commitment (not wrongly) to their willingness to use military force for some counterterrorism ends or simply describe endless wars in ways that focus on particular conflicts and tactics, like the presence of ground forces in Afghanistan.⁷ The counter-ISIS war shows how even limited uses of military force can generate a reemergence of preventive war logic. As long as the United States maintains interests in regions with resilient jihadist terrorist insurgencies, it will be at risk of snapback, where those interests act like a rubber band. You can stretch the American military posture back, but if it is still tied to the region, there are powerful psychological and material factors that can pull the United States quickly back into war—even with a restraint-oriented president.

Trump’s withdrawal from northeastern Syria has not eliminated the endless character of the war on ISIS. Instead, it is both the product of and helps to create conditions for the snapback of American military power. The American military continues to operate in parts of Syria as well as in Iraq. The administration has explicitly commitment to monitoring the situation for possible re-intervention.

The counter-ISIS war initiated on limited grounds is far from ending, instead settling into calls for a quasi-permanent presence to suppress ISIS, now that it is clear that the United States cannot annihilate the group. In the counter-ISIS campaign, the regional security rationale helped generate the broader preventive war logic. Meanwhile, calls for an American commitment to repeatedly police security in the Middle East themselves contribute to endless war.⁸

Successfully ending America’s endless wars will require more than a call for withdrawal. Instead, a call for the end of America’s ongoing wars must be combined with substantial policy efforts to change America’s vision of its role in the world.⁹ It will also require efforts to change the conditions on the grounds that give rise to effective and sustainable jihadist insurgency as well as the development and strengthening of non-military responses that can protect American interests. There is much ground for counterterrorism policy development and debate that does not foreground war as the primary response to resilient jihadist insurgencies. Such opportunities for policy development range from strengthening laws to prevent foreign fighter flows and efforts to counter jihadist organizing online to economic development and promotion of better governance in areas from which ISIS recruits to reforms to American bureaucracies tasked with bringing hostages home from conflict zones.¹⁰ In the meantime, policymakers should reexamine the preventive war logic basis for the war on ISIS and begin the work of reinstituting publicly accountable and transparent limits on when and how the United States will wage counterterrorism warfare.¹¹