Behind closed doors in Washington, President Barack Obama and his advisers are planning a strike against Syrian dictator Bashar al-Assad. Assad's Aug. 21 nerve gas attack against his own people, which Secretary of State John Kerry called "undeniable," cannot stand.

The U.S. must respond. But it must act in concert with other nations, reflecting the massive violation of international norms this horror represents. And it must temper Americans' expectations for the result.

If we've learned nothing else in more than a decade of war in the Middle East, it's that the U.S. cannot impose democracy and must face the fact that in some conflicts, there may be no good outcome. The aim here is to show that the world will not tolerate a government committing unspeakable crimes against its people.

The New York Times on Tuesday published a reconstruction of the attack that killed at a minimum hundreds of people, including many children: "Thousands of sick and dying Syrians had flooded the hospitals in the Damascus suburbs before dawn, hours after the first rockets landed, their bodies convulsing and mouths foaming. Their vision was blurry and many could not breathe."




But Assad's massacre of civilians is different. As Kerry said Tuesday, "This is about the large-scale indiscriminate use of weapons that the civilized world long ago decided must never be used at all, a conviction shared even by countries that agree on little else."




With enough support, including from Arab nations, it's appropriate for the United States to lead.