An intervention can always go awry, and there are legitimate concerns about the behavior of Syrian rebels. It is also true that an election year isn’t an ideal time for an intervention, although on this one Obama could work with Republicans to win bipartisan support.

Look, I’m no hawk. I was strongly against the Iraq war and the Afghan surge, and I’m firmly against today’s drift toward war with Iran. But Syria, like Libya, is a rare case where we can take modest steps that stand a good chance of accelerating the fall of a dictator. And after 17 months, there’s growing agreement that Obama should no longer remain a bystander.

“The Middle East needs U.S. leadership on Syria,” said R. Nicholas Burns, a former under secretary of state for political affairs, now a Harvard professor. “I’m a supporter of the president’s approach to the Middle East in general, but his administration has been entirely reactive on Syria. You hear from all the Arabs: ‘Where is the United States?’ ”

President Obama, your answer?