Vietnam

As Washington ponders how long to stay in Iraq, it would do well to remember the limited impact of the United States' withdrawal from Vietnam and Cambodia in the 1970s, Lebanon in the 1980s, and Somalia in the 1990s.

Public support for the war in Iraq has followed the same course as it did for the wars in Korea and Vietnam: broad enthusiasm at the outset with erosion of support as casualties mount. The experience of those past wars suggests that there is nothing President Bush can do to reverse this deterioration -- or to stave off an "Iraq syndrome" that could inhibit U.S. foreign policy for decades to come.

Despite recently signing the long-awaited trade deal with the United States, Vietnam's communist leadership is split by uncertainty about the country's economic and political future. Without an economic overhaul soon, Vietnam risks being relegated to the global dustbin. Officials, however, remain wary of too much international engagement and know that capitalism would destroy the one-party state. Change in Vietnam is inevitable. But it will occur through an evolution, not a revolution.

Newly released records show that L.B.J., for all his political canniness and cunning, never managed U.S. foreign policy well-even excluding the Vietnam War.