The numbers show that Republican isolationism -- and partisanship -- is growing.
"America acts more effectively abroad when we stand together," President Barack Obama argued in his Syria address to the nation on Sept. 10. In doing so, he echoed the foreign-policy establishment's belief that partisan politics must stop at the water's edge, a sentiment first expressed by Sen. Arthur Vandenberg, in a speech on the floor of the U.S. Senate on Jan. 10, 1945, as he announced his conversion from isolationism to internationalism.
It is not clear that such high-minded bipartisanship has ever driven Americans' views on foreign policy. In the early 19th century, Federalists and Democrats bitterly disagreed about relations with Britain and whether to support the French revolution. And there have been partisan differences over international affairs ever since.
What is notable today, however, is the degree of such partisanship and the accelerating pace of this polarization on key international policy issues.
In the current debate over possible U.S. airstrikes against Syria because of the Assad regime's alleged use of chemical weapons against its own people, a majority (63 percent) of the American public opposes any military action, according to a Pew Research Center survey conducted Sept. 4-8. But within that anti-bombing majority there is a 17 percentage point partisan divide: 70 percent of Republicans disagree with the Obama administration's proposed military action, but only 53 percent of Democrats are against it. And while Democratic opposition had grown by five points in a week, GOP opposition grew by 30 points.
Of course, where Americans stand on an issue -- such as whether it is Congress or the president who has the final constitutional authority to take military action -- often depends on whether the guy they voted for, or his opponent, sits in the White House. In 2002, in the run up to the U.S. invasion of Iraq, 58 percent of Republicans but only 26 percent of Democrats thought that President George W. Bush, rather than Congress, should have the final say in such military decision-making. Eleven years later, after a change of administrations, only 19 percent of Republicans, but 45 percent of Democrats think President Obama has the final authority to launch an airstrike against Syria.
These broad partisan differences mask a more revealing trend. While both Republicans and Democrats have changed their views on who should be the decision maker with regard to using force abroad, there has been a far greater shift in perspective by members of the GOP. Republicans have changed their stance by 39 percentage points. Democrats have moved by only 19 points.
And this is not an isolated case. Since the height of the Vietnam War, strong majorities of Americans have been inward looking, questioning the need for the United States to focus on international concerns. In 2002, in a Pew Research Center poll, 82 percent of Democrats thought "we should pay less attention to problems overseas and concentrate on problems here at home," one measure of antipathy toward internationalism. But just 66 percent of Republicans shared that view. By 2012, 80 percent of Democrats and 86 percent of GOP members held such sentiments, effectively no change by Democrats and a 20 point increase in isolationism by Republicans.
And this partisan divide over global engagement also manifests itself in views about engagement with China, arguably America's principal economic and strategic foreign counterparty. Fully 59 percent of Democrats believe building a strong bilateral relationship should be a top U.S. priority, according to a 2012 Pew Research Center survey. Just 48 percent of Republicans agree.
So, while it may be true that "America acts more effectively abroad when we stand together" and that partisan politics should stop at the water's edge, they don't. And if recent domestic debates over Syria are any preview of the future, bipartisanship over foreign policy may be in short supply.
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