An era marked by war and attempts at nation building is coming to its end.
President Obama has made clear he has no interest in lengthy foreign entanglements that would require large commitments of troops and defense dollars.
"We, the people, still believe that enduring security and lasting peace do not require perpetual war," Obama said in his inaugural address on Monday.
With U.S. troops out of Iraq and preparing to leave Afghanistan next year, the American public has little appetite at this point for taking on large-scale military interventions, says Rajan Menon, a political and international relations scholar at City College of New York.
"Obama is right about one thing," Menon says. "Most people want American presidents these days not to achieve some major transformation abroad, spreading democracy or defeating some foe. Instead, it's, 'Please don't put us in some multiyear quagmire, and please don't put us in some situation that costs us endless money that could be spent here.' "
But for all the desire to avoid quagmires, the U.S. continues to project its power abroad, often through special forces operations and drone strikes.
"This isn't an anti-interventionist mood, it's an anti-long-term commitment mood," says Jeremi Suri, a University of Texas historian.
While American presidents can sometimes pick their battles, events at other times may require military action, whether direct or indirect. The U.S., for example, began providing logistical support this week for France's ground offensive in Mali.
"People are inclined not to get involved," says Gary Schmitt, co-director of the center for security studies at the conservative American Enterprise Institute. "The caveat to that is that the world comes knocking at your door."
Cycles Of Intervention
Obama has signaled his desire to avoid fresh military adventures with his nominations of John Kerry to serve as secretary of state and Chuck Hagel as defense secretary. If confirmed, the two men, both Vietnam veterans, are expected to show more skepticism about foreign interventions than some of Obama's first-term advisers.
"I thought the president was very clear" in his inaugural address, says Maryland Democrat Ben Cardin, a member of the Senate Foreign Relations Committee.
"We have to be prepared to defend our values and use American strength to do that," Cardin says. "But now that we are completing our most recent conflict, the time has come to concentrate on the domestic."
American history has gone through repeated cycles regarding the question of military intervention, says Suri, the author of Liberty's Surest Guardian: Rebuilding Nations After War from the Founders to Obama.
Periods of heavy commitment overseas lead to a desire for retrenchment, while at other times there's a fear that the U.S. has become too isolationist and needs to re-engage.
Right now, the pendulum is swinging against intervention. "We're certainly not in a moment when it would be easy for the president to sell the public on a big, nation-building mission," Suri says.
There may be no desire on the part of the administration to bomb Iran to prevent its acquisition of nuclear weapons or to invade Syria in hopes of building a democracy there. But that doesn't mean Obama won't engage in military action during his second term.
"If the president really wanted to come home and not deal with the world, he wouldn't say that Iranian nuclear weapons are unacceptable," says Michael O'Hanlon, director of foreign policy research at the left-leaning Brookings Institution. "Once you say that, you might have to act, including militarily."
O'Hanlon argues that it's a symptom of "Potomac fever" for policymakers in Washington to believe that they can "control the flow of human history from our living rooms and our Oval Offices" — in effect wishing that world events will not suck the country into conflict.
Iran was on the nation's foreign-policy radar before Obama's presidency, but Syria and the whole of the Arab Spring revolutions were not. In other words, circumstances change. Something might very well happen in the next four years that would force Obama to order troops into harm's way.
"We're hardly ever in an interventionist mood in this country," O'Hanlon says. "Americans, in the abstract, would love to stay home and spend more at home, but you don't make decisions in the abstract."
From The Air
During his inaugural address, Obama promised to defend democracy abroad and work with international institutions to help manage crises. "America will remain the anchor of strong alliances in every corner of the globe," he said.
The U.S. already maintains sizable contingents of troops in more than two dozen countries. (The U.S. actually has troops stationed in more than 150 countries, according to Defense Department figures, but generally keeps a token presence of well under 100 service members in each.)
"The drug war we're fighting [in Latin America] is a massive military operation," Suri says.
Drone strikes have increased markedly on Obama's watch. Relatively cheap and precise, such air power has become a preferred method of combating terrorism.
"It's certainly cheaper," says Micah Zenko, a fellow at the Council on Foreign Relations who has studied drone attacks. "The dichotomy the administration puts forward is that we can put 170,000 troops on the ground, or we can do drone strikes."
But unmanned aerial strikes aren't necessarily an effective answer to long-term threats and may not alter political realities on the ground. And even when American sailors and service members aren't sent overseas, modern warfare may mean the presence of contractors or CIA personnel — such as during Libya's civil war and in Pakistan.
Drone attacks as well as the presence of Americans on foreign soil can lead to scenarios in which the U.S. military response steadily gets ratcheted up. History teaches that it is difficult to limit warfare, or certainly to control its outcome.
Avoiding situations that are most likely to lead to major deployments of troops appears, however, to be the president's desire at this point.
"There's absolutely no appetite for putting large numbers of, quote, boots on the ground," Zenko says. "This concern is something that will increasingly characterize U.S. foreign policy."