The Iowa caucuses finally are upon us, but presidential candidates have been pounding each other for months already about foreign policy: Toss out the Iran nuclear treaty! Make the sand glow in Syria! Start a trade war with China!

Most of the rhetoric is less than illuminating. So instead, let’s focus for a few moments on another debate, over how the next president should approach the rest of the world. It’s a theoretical argument, but it has real consequences. And it might just create a framework to think about all that heated campaign rhetoric.

Against intervention

Harvard political scientist Stephen M. Walt launched the debate this month with a piece published in Foreign Policy. You can read it here. But in a nutshell, he argues that many global trouble spots, and the U.S. itself, would be better off today if American presidents hadn’t tried to remake the world in the past 20 years.

In foreign policy circles, Walt is a “realist,” who argues that above all, conducting international relations is about having enough power to ensure your security in a hostile world. Here is a quote from his Foreign Policy piece:

Realists believe nationalism and other local identities are powerful and enduring; states are mostly selfish; altruism is rare; trust is hard to come by; and norms and institutions have a limited impact on what powerful states do. In short, realists have a generally pessimistic view of international affairs and are wary of efforts to remake the world according to some ideological blueprint, no matter how appealing it might be in the abstract.

That skepticism, he makes clear, applies to approaches followed by both neoconservatives and liberal internationalists. Hard-headed realists would not have invaded Iraq, he argues, nor engaged in nation-building in Afghanistan, vastly enlarged NATO (thereby antagonizing Russia), launched a bombing campaign in Libya and announced a “red line” against the use of chemical weapons in Syria because that country was not a vital U.S. interest.

Realists would be wary of a special relationship with Israel. They might have cut their losses in Afghanistan sooner. They would have pursued the nuclear agreement with Iran, but started earlier when Iran’s program was smaller, and might have ended up with a better deal.

It’s all about defining and pursuing what is narrowly in the national interest. While realism is a longstanding approach to foreign affairs, it’s also a rather dreary way of looking at the world that doesn’t really take into account America’s idealism, its sense of exceptionalism and its capacity to do good.

Is this what we want to be — should be? Would everyone be better off the U.S. approached the rest of the world more like, say, China does? Is the problem that the U.S. acted at all in these cases Walt cites? Or were some efforts worthwhile, but poorly thought out and executed? Is it a question of strategy, or of tactics?

In defense of a moralistic foreign policy

Walt asks why there aren’t more people who think like him writing for the opinion pages of major U.S. publications. Among those he called out by name is Roger Cohen of the New York Times, and Cohen answered a few days later.

Cohen acknowledges, for instance, that it is hard to make a case that vital U.S. interests were at stake in the Balkan wars of the 1990s. But he argues that the moral case for intervention was overwhelming. President Clinton did intervene, and if Bosnia is still a mess today politically, at least the fighting stopped.

Clinton still is haunted by another conflict that happened at the same time. While it was far from crucial to U.S. wellbeing, Clinton says that if he had acted sooner, the U.S. could have stopped the Rwanda genocide of 1994 and saved perhaps 300,000 lives.

Cohen also pushes back on NATO expansion, arguing that extending the alliance’s shield has protected countries along the Baltic coast and in Central Europe. The two countries in which Vladimir Putin has intervened militarily — Georgia and Ukraine — are not NATO members.

Take away the urge to expand liberty around the world, he says, and very little is left of U.S. foreign policy.

Realism unrealistic

At the Brookings Institution, Thomas Wright contends that realists like Walt have moved so far outside the mainstream that their ideas have little chance to be adopted. For decades, it has been a cornerstone of U.S. foreign policy to nurture institutions that bolster a U.S.-led international order. Organizations like NATO enhance cooperation among American allies who might otherwise find themselves at each other’s throats.

Amidst the chaos in the Middle East, concerns about terrorism and testy relations with Russia and China, Wright says those promoting a cautious policy aimed at strengthening that international order will be heard out in Washington.

Even if the U.S. is unlikely to pursue a foreign policy focused narrowly on self-interest, the questions remain: What are your priorities? How do you pursue them?

How is the best way to protect the homeland from international terrorists? Are you willing to hold your nose and do business with Putin? How important is it for the U.S. to be a force for good in the world, and how can you be sure the effort won’t backfire?

Good questions — to which good politicians probably will avoid giving a direct answer. But as the campaign goes on, they’ll give us some clues.