Obama: America Has 'Moral Obligation' to End Syrian Civil War

On the basis of what?

President Obama said Tuesday that the United States had both a "moral obligation" and a "national security interest" in ending the civil war in Syria.

But the president also said the "perceived" use of chemical weapons in the country was not enough to compel him to military action.

"My job is to constantly measure our very real and legitimate humanitarian and national security interests in Syria, but measuring those against my bottom line, which is what is the best interest of America's security," Obama said at the White House.