Neither argument is a good reason to launch cruise missiles, airstrikes or any other sort of war.
U.S. leaders obsess over credibility because of our many commitments to defend places where our interests are few. Because our forces are not infinite, the U.S. is like a bank vulnerable to a run. One failure can launch a self‐fulfilling prophecy of doubt. Therefore the U.S. must always show resolve, otherwise the dominos might fall: allies will lose faith and enemies will be emboldened.
One problem with this logic is that it lacks limits. No conflict is so remote that no foreign policy pundit has called it a vital test of U.S. resolve. Take Libya, for instance, which the Obama administration justified bombing partly as a demonstration that it would help the Syrian resistance.
If our credibility was so fragile, its protectors would oppose military commitments where U.S. interests are shaky. If U.S. credibility to defend Berlin from the Soviets during the Cold War was vulnerable to failure elsewhere, we should have avoided imperiling it by fighting a useless war in Vietnam. Likewise, fighting in Syria might undermine the war weary public’s limited support for fighting somewhere else, harming credibility. The fact that credibility is always a pro‐war argument shows that it is mainly a justification for war, not its motivation.
That is why airstrikes are unlikely to end the clamor about U.S. credibility. A volley of cruise missiles or conventional bombs will not win the war, but it will embroil us more deeply in it. Those that would fight now for credibility will then advocate the military escalation needed to achieve victory.
In this case, of course, it is too late to keep U.S. credibility out of it. You might agree that the president’s red‐line comment was foolish — that willingness to protect civilians should not depend on the means of their murder — but still think that, once the President said what he did, proven chemical weapons use compels military action.
But foolish words do not justify foolish actions. The larger problem with fighting for credibility is that war does little to protect it.
Historical studies show that foreigners do not assess U.S. willingness to intervene based on whether they carried out past threats. They focus, instead, on the local balance of military power and U.S. interests in their case. And leaders clinging to power are especially unlikely to care what we threaten to convince them to surrender it.
The humanitarian call for airstrikes is even less compelling. Strikes are more likely to prolong the civil war than win it for the fractious rebels. And even if they do win, the most likely outcome is milder anarchy, not a coherent state. Either outcome would likely worsen suffering, through widespread murder, a collapse of sanitation and health services, and the stunting of economic growth conducive to well‐being. Whatever the virtues of overthrowing Syria’s government, doing so cannot rightly be called humanitarian.
Neither the U.S. public nor the leaders now calling for war on Syria support steps sufficient to win it. The half‐measures being considered will exacerbate the credibility and humanitarian concerns said to justify intervention. The danger of making things worse makes military inaction prudent.