Associated Press
U.S. Secretary of State John Kerry, left, speaks during a joint news conference with his Jordanian counterpart, Nasser Judeh, right, in Amman Wednesday, May 22, 2013. Secretary of State John Kerry says the United States and its Arab and European allies will step up their support for Syria's opposition to help them "fight for the freedom of their country" if President Bashar Assad's regime doesn't engage in peace talks in good faith. (AP Photo/Mohammad Hannon)

Military intervention in Syria, in any form, comes with risks. But when the president of the United States draws a "red line," as Barack Obama did concerning the use of chemical weapons by the regime of Bashar al-Assad, the risks of not responding when such a line is crossed are worth considering, as well.

The United States maintains a special status in international politics as a superpower capable of standing up to human rights violators and threats to liberty. It cannot intervene in all cases, but it cannot promise to do so and then back down without a loss of credibility that would affect the way its allies and enemies conduct themselves.

Secretary of State John Kerry issued a tough statement Monday in which he said evidence that Assad launched chemical weapons attacks against his own citizens was "undeniable." Diplomats choose their words carefully. When Kerry said the attacks were a "moral obscenity" and that they ought to "shock the conscience," and when he said, "This international norm cannot be violated without consequences," he seemed to be laying the groundwork for a military response.

Exactly what that response would be, however, remains unclear. The administration appears unwilling to deliberately try to topple Assad's government. However, any missile attack meant as retribution runs the risk of also killing innocent Syrian citizens, much the same as what the regime's own attacks have done. A military strike would need to be strategic and surgical. Even so, it clearly would interject the United States further into Syria's internal conflict on the side of a nebulous rebel faction than may be desirable, and it certainly would inflame Russia, a clear ally to Assad.

The Obama administration seems to be working to put together a coalition of allies that would include France, the United Kingdom and others, gathering their united support for action. Such a strike would bypass the United Nations Security Council, where a Russian veto would doom any attempt to punish Syria. It also would bypass an ongoing U.N. inspection of the attack — one that attracted gunfire directed at the inspectors on Monday. For a Democratic president to bypass the U.N. much as Republican President George W. Bush did would further weaken the United Nations as a body capable of resolving disputes and punishing bad actors, but it is the only credible way to back up the president's "red line."

The troubling backdrop to all of this is that no one seems sure what Syria would look like if rebel forces were to topple the regime and assume power. There are few indications they would be any more inclined toward democracy, liberty and the protection of human rights than the current regime.

Clearly, however, the use of chemical weapons on civilians is unacceptable in any context. Syria is a pivotal nation in the Middle East with ties to Iran. The free world looks to the United States for leadership in such matters, and that is especially true when the president has set unequivocal conditions. Now, the administration must find a way to act both meaningfully and in a way that minimizes bloodshed.