"A president who has made clear to the American public that the “tide of war is receding” has also made clear to foreign leaders, including opportunists in Russia, that he has no appetite for a new one.”

Washington Post, this morning.

For much of his time in office, President Obama has been accused by a mix of conservative hawks and liberal interventionists of overseeing a dangerous retreat from the world at a time when American influence is needed most.

The once-hopeful Arab Spring has staggered into civil war and military coup. China is stepping up territorial claims in the waters off East Asia. Longtime allies in Europe and in the Persian Gulf are worried by the inconsistency of a president who came to office promising the end of the United States’ post-Sept. 11 wars.

Now Ukraine has emerged as a test of Obama’s argument that, far from weakening American power, he has enhanced it through smarter diplomacy, stronger alliances and a realism untainted by the ideology that guided his predecessor.

It will be a hard argument for him to make, analysts say.