Every once in a while, Chairman of the Joint Chiefs of Staff Martin Dempsey steps in to pour some much-needed cold water on the red-hot rhetoric in favor of escalating US military support against the Syrian regime of Bashar al-Assad. These days in Washington, Assad is the closest one gets to Osama bin Laden. No one has a good word to say about him. Even if there were, one would hardly dare suggest it, so unassailable are the moral choices posed by Washington. Whatever qualms exist about increasing US support for the opposition are a function of the opposition’s own shortcomings, from its political incoherence to the growing prominence of bin Laden wannabes in numbers that threaten to exceed anything in the last two decades. The list is long and getting longer by the day.

Changing the debate in Washington on the question of investing US power on behalf of the rebels is therefore no easy task, but Dempsey’s July 19 letter to Sen. Carl Levin (D-Mich.), chairman of the Senate Armed Services Committee, has done just that by forcing the policymakers to confront a fact that a majority of the American public, hesitant to invest US power in yet another Middle East military adventure, has almost instinctively grasped.

As Dempsey makes clear, there has never been a question about the ability of US military forces to accomplish whatever objective civilians set for it in Syria. American boots on the ground have, after all, occupied not a few Arab capitals in recent decades. None of the options for engaging the United States addressed by Dempsey in his letter is beyond the capacity of US forces, even forces facing billions of dollars in cuts and led by a national security team anxious to leave the ambiguous consequences of two decades of US military campaigns in the Middle East for the relative strategic clarity offered by a “pivot” to East Asia.

That, however, is not the point, Dempsey argues. As he informed Levin, “We have learned from the past 10 years … that it is not enough to simply alter the balance of military power without careful consideration of what is necessary in order to preserve a functioning state. We must anticipate and be prepared for the unintended consequences of our action. Should the regime's institutions collapse in the absence of a viable opposition, we could inadvertently empower extremists or unleash the very chemical weapons we seek to control.”