By Bruce Stokes, Director of Global Economic Attitudes, Pew Research Center

Special to Foreign Policy

“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.