U.S. President Barack Obama's weeks of fumbling during the Syrian chemical weapons crisis may create dangerous uncertainties for Japan during the rest of his presidency.

From the moment Obama announced his intention to consult with Congress about a military strike, he seemed to have scored a damaging own-goal. Abstaining from military action would make his earlier tough talk about "red lines" look like empty bluster. To strike after a "no" vote in Congress would attract blame at home and abroad. And even to strike with congressional approval wouldn't erase questions about whether the delay diminished the strike's tactical efficacy. (To say nothing of the problem that such a strike would violate the United Nations charter.)

Was congressional approval even needed in this situation? Back in 2008, Senators Obama and Biden asserted the U.S. Constitution requires it; but now Obama, like most presidents before him, claims otherwise. He didn't consult Congress before the 2011 bombing of Libya, for example. So why do so now? Maybe to find a face-saving way to back down from his red-line ultimatum, after all. But then why lobby members of Congress and go on television to drum up support for a strike? As Machiavelli noted several centuries ago in his Discourses on Livy: "One should not make threats first and then request authority." To do so, he wrote, is simply stupidity.