The visit of Vietnamese Prime Minister Phan Van Khai, 71, to the United States and President George W. Bush's acceptance of his invitation to pay a return visit to Vietnam next year are fine signs that the war and its aftermath are moving from the category of irritant, into history.

Many Americans might wish that the Vietnam war had become even more distant history before the 2004 presidential campaign. There were moments last year when the impression was given that what was being contested was the Mekong Delta, not Ohio.

The United States provided Vietnam during the visit an important leg up in meeting its primary problem, achieving greater and faster economic development, by expressing enthusiastic support for its bid to join the World Trade Organization.

At the same time, Vietnam's being required to meet the demands of economic liberalization incumbent on members of the WTO will also oblige it to deal with what is the main constraint in its efforts to join the other Asian tigers of development, an economy that is still run basically by a bunch of old communists.

Vietnam still lags behind Southeast Asian countries like Thailand, not to mention neighboring China, in strides forward in modernizing its economy. China also still has single-party, communist government but its leadership has less and less let that stand in the way of an economic great leap forward. Vietnam is getting there, but hasn't yet arrived.

Its monolithic communist government is responsible also for the country's considerably less than sterling human rights record. The Hanoi government is moving beyond the immediate mean post-war approach to consolidating the former South Vietnamese under its rule, but scars and some not yet healed wounds remain. The affair, after all, ended only 30 years ago.

It is also inevitable that a cloud will still hang over the United States side of the relationship from the war. The American public was recently regaled with a heavily advertised television presentation that was part of the 2008 presidential candidate possibility exploration of former prisoner-of-war Sen. John McCain, D-Ariz. The show included a prominent role for his Vietnamese torturers.

And there remain also the South Vietnamese exiles in the United States, those to whom America gave refuge concurrent with and after the collapse in Saigon. Some of them have made their peace with the Hanoi regime; some, quite understandably, have not.

All in all, the improved U.S. relations with Vietnam that Mr. Khai's visit represents constitute a success in Mr. Bush's Southeast Asian diplomacy. Vietnam is already a healthy U.S. trading partner, with $6 billion in two-way trade last year. Mr. Bush's visit to Hanoi next year, to attend the Asia-Pacific Economic Cooperation forum summit as well as to visit Vietnam itself, are important steps forward in cementing relations with what can become an important U.S. partner in that region.