Why Americans Aren't as Willing to Intervene Overseas as They Used to Be

President Obama faces a radically different public-opinion environment than he did even two years ago, when the U.S. prepared to act against Muammar Gaddafi's forces in Libya, as he seeks to make the case for an attack in Syria. Why are things so different now? It's not as simple as that the public is "war-weary," as is frequently said. Here are some of the other forces I believe to be at work:

1. 9/11 is a distant memory. The threat of terrorism once exerted a strong sway on Americans, creating an automatic bias toward action. That's no longer the case. This is good! It's a sign of the success of the more than decade-long campaign against al-Qaeda. But it also means that the emotional backdrop of our thinking about external threats and obligations has shifted. In the wake of Edward Snowden's revelations, in particular, Americans are in the thick of a moment of reconsidering what they agreed to -- and what was done without their knowledge -- in their moments of greatest fear, and not an era of fearfully agreeing to things without debate. When George W. Bush warned in 2002 "we cannot wait for the final proof, the smoking gun, that could come in the form of a mushroom cloud," his warning came against the backdrop of orange alerts and panicked runs on hardware stores for plastic sheeting and duct tape. Times have changed, and without engaging in Bush-style fearmongering about threats to the homeland or making a humanitarian case for intervention, as in Libya, it's going to be harder for any political leader to sell the once-burned, twice-shy public on the need for rapid action abroad.

2. It's a new Congress. Three wave elections after the push to war in Iraq, we have a quite a different Congress. National Journal's Shane Goldmacher reports: "Only 32 current senators served in 2002 during the fall vote on the Iraq war resolution and only 38 were there when American troops launched the invasion in the spring of 2003. In the House, roughly 40 percent of current members -- 172 of them -- were sworn in at the time of the 2003 invasion. That means that, for many in the current Congress, this is the first time they've experienced the drumbeats of war, outside of the strikes that Obama authorized against Libya earlier in his presidency. And instead of marching in line, the fresh faces are among those most loudly demanding a public debate." On the Democratic side, in particular, you have a fair number of folks who were elected -- like Obama himself -- in hopes that they would take a different approach to foreign policy than Democrats took in the early Bush years. They are now doing that.

3. The cost of raising questions is low, for the moment. Congress is on vacation. As Keith Koffler smartly points out, it is not going to come back to town until September 9 unless Obama or its leaders force it back. "Our elected representatives today are on Caribbean Islands and rolling green golf courses, or wandering about delightfully quaint European cities. They have no intention of breaking it off to come back and vote on some silly war. That's why you don't hear their leaders clamoring for Obama to stage a vote -- they'd be jeopardizing their positions as leaders," he notes. The people who are pressing Obama to call an emergency session of Congress might also think of calling on Speaker John Boehner and Majority Leader Harry Reid, who thus far have not publicly indicated any need to reassemble their legislative bodies. As it is, talk is cheap for at least one more week. So is silence. While 116 members of the House have called on Obama to seek congressional approval before taking action in Syria -- a move that 80 percent of the public supports -- the outcome of White House's Syria briefing with 27 of the 535 members of Congress Thursday night was a call for the administration to do more to sell its proposed intervention, not a flurry of efforts to force a return to Washington ASAP and a vote.

4. Obama never has to stand for election again, but the jockeying for 2016 is well under way. It's possible Obama's intervention in Libya would have earned louder opposition from Democrats and liberals if the president had not also still faced reelection, which doubtless tempered some voices. That he won't again opens up the floodgates of criticism from people who expect to be standing on the political stage long after he is gone, as well as by some who hope to take his chair.

5. There's no longer widespread optimism about the Arab Spring. It was easier to make the case for intervening in the Arab world against monstrous, human-rights-violating dictators when there was the hope of democracy or any kind of positive outcome on the other side. Between the Morsi regime's spectacular failure and the subsequent military coup in Egypt and the extensive instability in Libya that led to the death of a U.S. ambassador in Benghazi (even if U.S. intervention succeeded in saving Libyan lives) the argument that the U.S. can pick sides in Arab nations in a way that's beneficial to either our interests or the well-being of Arab peoples long-term has been deeply damaged.

6. The moral argument for why chemical weapons are different is no longer as obvious as it once was. One of the trickiest arguments for the administration to make to the public is why it's worse for Assad's forces to kill children with sarin gas than to drop an incendiary napalm-like bomb, also made with chemicals, on a school, or to gun families down in the street. Morally, the outcome is the same -- death, injury, and suffering of innocents -- and if gas survivors struggle with after-effects for life, the same is also true for those who survive guns and bombs. Since World War II, poison gases have been used mainly in the Middle East. The Chemical Weapons Convention, which states that "each state party to this convention undertakes never under any circumstances ... to use chemical weapons" and to which Syria is not a party, was signed only in 1993. This 20-year-old treaty seeking to enforce the post-World War II international norm against chemical weapons use does not appear to have a great deal emotional resonance for the American people, now so many generations removed from the horrors of World War I, the great chemical-weapons build-up of the Cold War, and Hitler's gas chambers.

Update: Fallows adds one more, namely, "We've been at war now for 10 years non-stop, the longest period of such sustained engagement in American history. Not to mention, those wars have not turned out well."