U.S. military forces are stretched painfully thin, with large-scale deployments bogged down in Afghanistan and Iraq. The Pentagon’s enormous budget is under scrutiny, with increasing numbers of Republicans joining Democrats in demanding deep cuts. And polls consistently show that as we near the 10th anniversary of the Sept. 11 attacks, with Osama bin Laden dead, the American public is weary of war.

The call for Assad to go, then, appears more symbolic than substantive. You can’t call it pure theater, since it does put additional pressure on the regime and lays the groundwork for further sanctions. But if everyone knows that Assad won’t leave — and that we won’t make him — the demand from the White House sounds like an extremely tardy statement of the obvious.

What we need is something the president has refused to provide: an Obama Doctrine governing the use of force to defend civilians against their own despotic governments, or at least spelling out how the United States views its role in the unfolding Arab Spring.