A Washington Post story on the nomination of Susan E. Rice to be ambassador to the United Nations illustrates the intellectual and moral challenges facing liberal internationalists.

In the article we learn this:

[Rice] has voiced a commitment to use American muscle to protect human rights in Africa, particularly in Darfur, where she has raised the prospect of a naval blockade and a bombing campaign to compel the Sudanese government to halt mass violence.

Rice has spoken movingly about how she was shaken by the genocide in Rwanda, where as many as 800,000 were killed. Describing a 1994 visit to the country, Rice told Stanford University‘s alumni magazine that she saw “hundreds if not thousands of decomposing corpses outside and inside a church. Corpses that had been hacked up. It was the most horrible thing I’ve ever seen. It makes you mad. It makes you determined.”

Since then, Rice has said she has been haunted by the United States’ failure to intervene or to reinforce a beleaguered U.N. peacekeeping mission in Rwanda on the eve of the genocide.

But we also learn this:

Rice, 44, says her connection to Obama was forged in part by a shared opposition to the war in Iraq, but she is the only top figure in Obama’s national security team who opposed the war.

And this:

U.N. officials welcomed the selection of Rice, an unapologetic proponent of multilateralism

So what’s wrong with this picture? For one thing, we are told Rice is a fierce advocate for human rights–yet she opposed the war to liberate Iraq, which overthrew one of the most sadistic figures in the last half-century, an architect of genocide, and the aggressor in wars against Iran and Kuwait. If Ms. Rice had had her way, Iraq would still be ruled by Saddam, rather than be on the road to self-government. And if Ms. Rice and President-elect Obama had both had their way, the surge would never have happened, all American combat troops would have been withdrawn from Iraq by March of this year, and Iraq would have slid into a civil war and experienced mass death and perhaps genocide.

We read Ms. Rice is an “unapologetic proponent of multilateralism”–yet it is a commitment to multilateralism that so often hamstrings nations from acting to stop genocide in nations like Sudan, Rwanda, Iraq, and elsewhere.

Multilateralism has its benefits, but it also has some striking drawbacks. Among them is that in trying to assemble a large coalition, often the consequence is that nations like Russia and China, as in the case of Darfur, will create obstacles to effective action. The more nations that are involved, the greater the possibility is of foot-dragging, delay, and outright obstructionism.

Ms. Rice and Mr. Obama are transitioning from commenting about what should be done to actually governing. The difference is enormous, and soon enough they will experience first-hand the conflict between their desire for multilateralism and their desire to achieve an admirable moral end.

For example, what happens if acting to prevent genocide is opposed rather than supported by the U.N. Security Council; that it strains rather than strengthens our relations with other nations; and that acting requires us to reduce rather than enlarge the size of an international coalition?

Insisting that we should “rally the world” to stop genocide won’t be enough. Ms. Rice will discover again, as she did during the Clinton years, that much of the world is indifferent to genocide and other evils. (Rice herself says she has been haunted by the United States’ failure to intervene or to reinforce a U.N. peacekeeping mission in Rwanda on the eve of the genocide, which killed approximately 800,000 people in 100 days.) And then she and President-elect Obama will have to choose between imperfect options.

In a December 17, 1962 interview, President Kennedy was asked whether his experience in the office matched his expectations. He answered this way:

The problems are more difficult than I had imagined them to be. The responsibilities placed on the United States are greater than I imagined them to be, and there are greater limitations upon our ability to bring about a favorable result than I had imagined them to be. And I think that is probably true of anyone who becomes President, because there is such a difference between those who advise or speak or legislate, and between the man who must select from the various alternatives proposed and say that this shall be the policy of the United States. It is much easier to make the speeches than it is to finally make the judgments. . . .

Indeed it is.