The rhetoric surrounding U.S. foreign policy is often infused with grandiosity, as if the United States would have the power to determine the fate of nations if only it had the gumption.

The Arab Spring is a humbling reminder of the limits of American power and also its usefulness. Now the conflict raging in Syria presents the Obama administration with a serious challenge to its diplomatic wisdom and skill.

History is littered with disasters caused by policymakers with an inflated sense of their own intelligence and a dangerous infatuation with American power. Vietnam is the great example of imperial overreach, when the United States came in on the losing side of a civil war that had no bearing on American interests.

The second great disaster was the Iraq war, where we learned that it is easy to go into a country, to defeat its military and destroy its institutions, but that it’s a lot harder to leave behind a state capable of functioning within the rubble.

As with Vietnam, the Iraq war was justified on the basis of inaccurate analogies. The Johnson administration was mindful of European attempts to appease Hitler and so thought it was best to stand up to the advance of communism in Southeast Asia.

The Bush administration used a different analogy with regard to Iraq: They decided that the Iraqis would build a democracy out of the wreckage of war the way that Germany built a democracy after World War II. It didn’t work out that way.

Now unrest is rolling through the Middle East, and Republican presidential candidates, hoping to appear forceful, have been sending out bellicose messages about Iran and about the need to back Israel, right or wrong. They tend to attack President Obama either for doing too little or too much. In fact, Obama has demonstrated the advantages to be gained by avoiding threatening rhetoric that might suck the United States into costly and futile engagements.

He helped defend insurgents in Libya, leading to the toppling of the most oppressive regime in the region. Once he saw the flow of events in Egypt, he allowed for the removal of Hosni Mubarak. Insurgents in Bahrain have gained rhetorical support, but Obama has not risked challenging the Bahraini regime because of the importance of the U.S. naval base there. The best he can do without undermining our strategic interests is to counsel moderation.

Syria is in the midst of a serious crisis that touches on all of its neighbors, including Lebanon, Israel, Turkey, Jordan, Iraq and Iran.

All of these forces have different interests at stake in Syria, and the United States has an interest in preventing the conflict there to widen into a broad regional conflict. Our democratic values also compel us to prevent a more serious humanitarian disaster and to try to foster political progress.

Because overt U.S. intervention often makes matters worse (see: Iraq), it is often in U.S. interests to pursue our aims behind the scenes (see: Libya). In the meantime the regime of Bashar Assad is carrying out a punishing bombardment of civilian neighborhoods in the city of Homs, a campaign of suppression echoing the brutal slaughters enacted by his father.

The danger is that Syria will descend into a civil war in which all the neighboring nations would back competing factions. A broader, prolonged war would create a humanitarian disaster wreaking human and economic damage that could spread throughout the region.

Behind-the-scenes maneuvering to avert disaster requires shrewd thinking. If Obama can juggle all the balls at the same time, he could use the weakness of Assad to apply pressure to Iran, an Assad ally, to comply with U.S. aims to curb its nuclear program. The weakness of Syria, as it crumbles under the weight of civil war, could conceivably help Israel, or it could lead to regional strife that harms Israel.

The absence of bellicose rhetoric from Obama is a sign of U.S. strength, fueling the hope that smart diplomacy is under way.