For lawmakers, it is much easier to sit at the other end of Pennsylvania Avenue and critique the president's performance - and there are no great outcomes on the horizon for the morass that is Syria - than to go on the record as either supporting or opposing military strikes. Obama's decision means that Congress won't have the luxury of having it both ways, criticizing the president for inaction in the face of great carnage while also opposing U.S. involvement.
For Democrats, the vote will be a tough one. They will be torn between a humanitarian impulse and loyalty to the president on one hand and general aversion to military interventionism on the other.
For Republicans, it is even trickier. It pits their impulse toward neoconservatism and the United States asserting its authority on the global stage against the libertarian, populist, even isolationist impulse. Particularly fascinating will be how Republican senators who are potential presidential candidates handle the issue, namely Rand Paul, Ted Cruz and Marcio Rubio.
The president, meanwhile, seems to be betting that the effort to obtain congressional buy-in will ultimately make him, and his Syria strategy, stronger, rather than weaker.
But he has also, by turning to Congress, unleashed Syria as a more open public debate than it would have been if he had just launched strikes. It also leaves him in a strategic cul-de-sac if Congress ends up rejecting the strategy.
He has said it is the right thing to do, and that he has the authority to launch strikes without congressional authority if he sees fit. What does he do if it loses? Leave the French to launch strikes on their own, or explicitly defy Congress? Neither is a great option.
In foreign policy, as in life, it can be better to ask forgiveness than permission. But Obama has chosen to ask for permission instead.