Do It, But Do It Right.

Tepperman is senior editor at Foreign Affairs magazine in New York.

At each stop on his Africa tour last week, President George W. Bush hinted--without quite committing himself--that he's about to send peacekeepers to war-racked Liberia. The move shocked diplomats and policy experts, even as it overjoyed most Africans. After all, Bush came to office heaping scorn on peacekeeping and declaring Africa outside the U.S. national interest.

Why the reversal, then? Has the White House suddenly found religion? Or is it just trying to burnish its post-Iraq image by showing the world that it really does care about human misery--even when oil is not involved?

The answer matters little to Liberians, who care only that Bush does the job right. This is no small order, however; as Bush is slowly learning in Iraq and Afghanistan, merely keeping the peace in a chaotic land is extremely difficult.

Luckily, recent history provides a handy guide for what not to do in Liberia. Bush must avoid the mistakes that doomed the last U.S. foray into Africa: the 1992 intervention in Somalia. Bush's father dipatched 25,000 soldiers to deliver aid. The GIs' deployment was soon drastically cut, however, even as their mission expanded. The result, predictably, was a disaster. On Oct. 3, 1993, a group of underequipped U.S. Army Rangers was ambushed in Mogadishu, and 18 were killed. Bill Clinton, who by then had become president, quickly pulled out the rest.

Although there's no foolproof way to avoid a similar result this time, a few basic steps can dramatically improve the odds. For starters, Bush must fight the temptation to intervene on the cheap. This means using ample troops, with a clear sense of mission and enough heavy armor to protect them. Never mind Bush's statement that he'll get involved only once Liberians sign a ceasefire and their bloodthirsty president, Charles Taylor, steps down. Taylor is known for breaking promises, and truces in this region tend not to last. If the U.S. military goes to Liberia, it will soon end up making peace, not keeping it.

Unfortunately, Bush seems not to recognize this. American officials predict he'll send only 500 to 2,000 soldiers, backed by an unknown number of regional troops. A U.S. ...