But it’s important to recognize just how unprecedented such a vote would be, and how far the ripples might ultimately spread. It wouldn’t just be a normal political rebuke of President Obama. It would be a remarkable institutional rebuke of his presidency, with unknowable consequences for the credibility of American foreign policy, not only in Syria but around the world.
Presidential credibility is an intangible thing, and the term has been abused over the years by overeager hawks and cult-of-the-presidency devotees. But the global system really does depend on other nations’ confidence that the United States means what it says — that the promises the White House and the State Department make are binding, that our military commitments aren’t just so much bluster, and that when the president speaks on foreign policy he has the power to live up to his words.
It’s true that we can’t know for certain what the consequences of a no vote would be, but we can be reasonably sure that it won’t include the parade of horribles that advocates for intervention have been describing in the last three weeks. There is no reason to think that anyone will doubt U.S. security commitments elsewhere in the world, and it seems very far-fetched that refusing to attack Syria now will prompt other governments to start amassing or using chemical weapons. Authoritarian regimes that have resisted U.S. demands in the past will continue to do so for their own reasons, but it is implausible that they will determine their future behavior based on how the U.S. treats the Syrian government in this case. In short, the commitments that the U.S. has seriously made and kept for many years or decades are not in jeopardy, but the ability or at least the willingness of the president to commit the U.S. to military action through careless and ill-conceived rhetoric may be constrained. As Jim Manzi pointed out, this is a feature, not a bug.
The problem with talking about credibility is that the discussion tends towards vagueness. When pressed to give examples of how lost credibility would be damaging to the U.S., the examples are almost always absurd and easily dismissed. The more specifically that we focus on individual issues, the more we realize that credibility (like “resolve” or “leadership”) is a term that is used with the greatest frequency when the merits of a specific policy proposal are lacking. When a policy doesn’t make sense to most people, advocates have to fall back on warnings about lost credibility. They do this not so much because they believe that U.S. credibility elsewhere is at stake, but because they want to obscure the flaws in the policy they are promoting.
It’s worth recalling that most of the real damage done to America’s reputation and its ability to conduct an effective foreign policy came from policy decisions that committed the U.S. to take action in several ways that trampled on international law and imposed enormous fiscal and human costs on the U.S. and the countries affected by those decisions. Whether it is torturing detainees, holding people in indefinite detention, or launching illegal wars, we have seen the kinds of behavior from the U.S. that actually undermines relationships with other countries and destroys America’s reputation even in allied countries, and even after doing all these destructive things U.S. foreign policy was not “crippled.” It is inconceivable that refusing to attack another country would cause the U.S. very much grief at all. As for Obama, he will suffer politically from a no vote, but it is also possible that he will then be able to shut the door to any greater U.S. involvement in Syria for the rest of his time in office. If he does that, that would make the next three years much less risky and dangerous for the U.S. than they would be following a U.S. attack.