The foreign policy issue in American politics has undergone some remarkable shifts over the years. We are in the midst of just such a shift, but before we can properly understand what is happening today we must consult Clio, the muse of history, and see what patterns we can discern.

As witnesses to the birth of the American empire at the turn of the last century, the two major parties staked out roughly opposite positions. As William McKinley and Teddy Roosevelt presided over the acquisition of Hawaii, Puerto Rico, the Philippines and Cuba, it was the Republicans – the party of big business, crony capitalism, and "preparedness" – who waved the banner of expansionism, and the populist Bryanite Democrats who stood for anti-imperialism. This changed with the usurpation of the old Democratic populism by the "progressivism" represented by The New Republic and Woodrow Wilson, whose policies would christen an entire school of foreign policy thought under the rubric of "Wilsonian" internationalism.