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Americans appear to be less interested in U.S. foreign engagement that at any other time over the last half-century, judging by a Pew poll that has been measuring U.S. public opinion since 1964. The poll found an all-time low in public support for an active U.S. foreign policy, as well as a growing desire to focus away from the world stage.

The most striking poll result is the share of Americans who believe that "the U.S. should mind its own business internationally and let other countries get along the best they can on their own." For the first time since Pew began asking in 1964, more than half of respondents say they agree with that statement, a staggeringly high 52 percent. That number has historically ranged between about 20 and 40 percent. The share who said they disagreed with that statement is now only 38 percent.

Another metric found similar record highs in isolationist attitudes. When asked if they agreed that the United States should "not think so much in international terms but concentrate more on our own national problems," 80 percent surveyed said they agreed, an all-time high. Only 16 percent disagreed.

Two other major spikes in U.S. isolationist attitudes occurred during periods of economic recession: in the mid-1970s and early 1990s. It's not clear how much those attitudes were driven by domestic economic slumps versus foreign policy challenges abroad, such as the 1973 energy crisis. But neither of those matched the current trend, which has been rising since 2005, when the U.S.-led war in Iraq started turning really bad. Most likely, what may have begun as a backlash against the Iraq War has been accelerated and exacerbated by the 2008 recession.

That rising American desire to disengage with the rest of the world isn't just an interesting piece of information – it could have a real impact on the world. U.S. presidents often turn to foreign policy in the second halves of their second terms, especially when the opposition party holds one or both houses of Congress. And there's been much speculation in Washington that President Obama would do the same. But he may find himself challenged by an American public that wants exactly the opposite. These poll numbers reflect American public attitudes that are widely and strongly enough held that they could indirectly steer the White House, thus affecting U.S. foreign policy and perhaps the world itself.

Obama already ran into this problem, for example, with his plan this fall to launch limited strikes against Syria as punishment for its use of chemical weapons against civilians. Overwhelming public opposition and overwhelming Congressional opposition fed into one another, ultimately killing the plan. Even though the strikes would have been modest compared to almost every other U.S. military action of the last 10 years, they were opposed far more vociferously, and that mattered. Whether Obama's plan was a good or a bad one, the point is that his approach to Syria – and perhaps the course of the Syrian conflict itself – was to some degree altered by American public opinion.

This does not mean that the country is headed for another period of 1930s-style isolationism or that the U.S.-dominated global system is about to be left suddenly adrift. But it would be reasonable to anticipate that this attitudes will exert a pressure on the Obama administration and on Congress that will make U.S. foreign policy less assertive. In cases where the country is on the fence between action and inaction abroad, this remarkable rise in isolationist attitudes could bend the administration to inaction. Given that the United States probably plays a more active and important role on the world stage than any other country, that could have non-negligent ramifications for the rest of the globe.

There are other trends in the data that point to rising isolationism. Perhaps unsurprisingly, Republicans tend to be more critical of U.S. global leadership when a Democrat sits in the White House; the same is true of Democrats when a Republican is president. So today's isolationism is highest on the Republican side. Still, even correcting for this partisan tendency, indicators of American isolationism are at an unusual and perhaps unique high across the board.

Reinforcing Americans' views that the country shouldn't be active abroad is the growing impression that the United States just isn't as capable. More than half of Americans, 53 percent, say that the United States is "less important and powerful as a world leader than it was ten years ago." That's the highest proportion of respondents to say as much since Pew started asked the question in 1993; it's highest among Republicans, 74 percent of whom say as much. Similarly, a staggering 70 percent of respondents say that the United States is "less respected" abroad than it has been in the past.

Slightly more than half of Americans say that the country tries to do too much in "solving the world's problems." Interestingly, this metric has an unusually low partisan divide; 52 percent of Republicans and 46 percent of Democrats said they agreed the United States does too much. They may get their wish.