Editor's Note: This guest post is the first in a series of three posts about the changing face of American foreign policy. They are based on ideas explored in a new book by Kim R. Holmes titled Rebound: Getting America Back to Great, to be published in November. Holmes served in George W. Bush's administration as assistant secretary of state for international organization affairs and is now a distinguished fellow at the Heritage Foundation.

For decades Americans have been deeply divided over foreign policy. Since the Vietnam War they have argued over everything from wars to nuclear weapons to the purposes of foreign aid. However, today changes are afoot. Conservatives like Sen. Rand Paul join liberals in denouncing the surveillance policies of the National Security Agency. "Neoconservative" Sen. John McCain condemns Paul as an "isolationist" and embraces liberal Samantha Power's appointment as U.S. ambassador to the United Nations. Spending on defense, once the sacred cow of national security conservatives, is dropping rapidly as a result of a bipartisan deal on sequestration.

Something new is going on here. Old battle lines are being redrawn as Americans deal with the challenges of a new world. It may be possible, for the first time in a very long time, to review fundamentally the country's foreign policy. If not a realignment of views, then at least a new look at U.S. foreign policy may be possible.

Until recently we had roughly three ways of looking at America's role in the world. As worldviews they have dominated the way U.S. foreign policy has been debated and even made. Let's take a look at them briefly before we examine how they are changing.

The first of these I call "pull back" -- as in significantly downsizing America's presence abroad. The main premise is that American foreign policy is too militaristic and overly involved in trying to control events overseas, particularly with military force. In academia, proponents include such people as Barry Posen at the Massachusetts Institute of Technology, John Mearsheimer at the University of Chicago, and Andrew Bacevich at Boston University. In the political world its supporters range from Rep. Barney Frank on the left to Ron Paul on the right, and some libertarians. Think tanks likewise break down in this fashion, with the Center for American Progress on the left and the Cato Institute on the right. Their critics tend to label them as "isolationists," but in reality they don't want to withdraw completely from the world, but only to scale down dramatically America's military activities overseas.

The second framework can be called "retrenchment." This most closely resembles the foreign policy of President Barack Obama, who pays lip service to international idealism but who in practice is pragmatic and quite inward looking. The dominant theme is that American power is increasingly limited and must adjust with less interventionism and a smaller military footprint overseas. As the president said in a January interview with the New Republic, "I am more mindful probably than most of not only our incredible strengths and capabilities, but also our limitations." There is a rhetorical commitment to traditional American engagement and, in the war on terrorism, even a hawkish streak of unilateralism. However, in practice the main focus is domestic policy, or as Obama put it, to concentrate on "nation-building here at home."

A third is that of the conservative hawks. Sometimes called neoconservatives, they are the interventionists who believe that American power is being tested all over the world and any failure to respond sends a signal of weakness that adversaries will exploit. They possess a heavy streak of moralism, which is often deployed to justify military interventions. The Syrian civil war, for example, is decried as both a strategic threat to American interests and an offense to Americans' moral sensibilities. Adherents include many officials who served in George W. Bush's administration, some scholars at the American Enterprise Institute; opinion writers at the Weekly Standard, academics such Fouad Ajami of the Hoover Institution, and Max Boot of the Council on Foreign Relations. Their main political protagonists today are Senator McCain and Sen. Lindsey Graham.

I fully realize these categories are not all-inclusive. Scholars, experts, and even politicians have nuanced views that are impossible to pigeonhole. Moreover, some may disagree with my characterization of their views. However, my purpose is not to establish ironclad "schools of thought" but rather to provide a framework to explore how some of the views held by people in these groups are migrating, as it were, ideologically. Because of changing public opinion about wars and national security in general, the neatness of these categories is fraying at the edges, allowing for some rather unusual ideological bedfellows.

I will explore how this is happening in the next installment in this series. As we will see, these categories are fraying at the edges. It is not easy anymore to tell exactly who is liberal or conservative in foreign policy. Because of this there may be a chance for if not a full realignment of views -- that is probably not in the cards -- at least a "new look" that could present some interesting possibilities.