There are any number of defensible arguments in support of President Donald Trump’s decision to withdraw U.S. troops from northeastern Syria. It is safe to assume that Trump didn’t consider any of them. Instead, Trump seems to have acted as ever on impulse, out of a misguided sense that his instinct is a better guide than strategic planning and historical literacy. His decision reveals not an infallible instinct but a failure to understand three core elements of American power: assurance, deterrence and leverage.
To begin with the theoretical arguments in support of withdrawing from northeastern Syria, first and foremost, the U.S. has no essential national interests at stake there. The U.S. deployment that began in late 2015 accomplished a number of valuable goals inexpensively, including militarily defeating the Islamic State, and keeping Syrian, Russian and Iranian-aligned forces out of the area. But the presence of American troops there and the partnership on the ground with Syrian Kurdish militias were ad hoc arrangements that were never meant to be more than temporary. After the defeat of the Islamic State on the battlefield, the many problematic aspects of America’s partnership with Syrian Kurds—namely the ideology of their most potent militia, the YPG; its ties to the Kurdistan Workers’ Party, or PKK; and the perceived security threat the YPG poses to Turkey—took on newfound significance.
Nevertheless, given the volatility of the situation on the ground and the power vacuum that U.S. forces would leave in their wake, all these arguments presupposed a measured withdrawal in proper order at the appropriate time. In this way, security assurances could be provided to both America’s erstwhile Kurdish partners and its NATO treaty ally, Turkey; the gains against the Islamic State preserved; and Syrian and Russian forces prevented from entering the area.