Remembering the bitterness in the aftermath of the war in Vietnam, it is astonishing that four American veterans are now in Hanoi discussing, among other things, the lingering problem of US servicemen still missing in action. Astonishing and heartening. It would be premature to expect from the talks a quick or early resolution of the problem. But the very fact that Vietnam invited the Americans suggests it may be ready for a constructive dialogue with the United States. If so, Washington should itself be preparing for the possibility.
What is behind Hanoi's gesture on the MIAs? Probably both external and internal factors are involved. On the foreign front, it can reasonably be assumed that Vietnam would like some easing of the pressures from China by getting away from such heavy dependence on the Soviet Union. This would require opening up some link with the United States and that, in turn, necessitates a forthcoming move with respect to the MIAs - a matter of such emotional concern to the American people. Inviting a private visit thus seems a logical place to start.
Internally, too, pressures may be building for a normalization of ties with Washington. Vietnam's economy is in terrible shape, and the Soviet tie clearly has not produced a palpable improvement for the Vietnamese people. There is little doubt that Hanoi would be as eager as any other communist capital to profit from economic links with the West.
Formidable diplomatic problems stand in the way of US-Vietnamese ties, however, and the Reagan administration has lost no occasion to criticize the Hanoi government. Of paramount concern is Vietnam's close relationship with the Russians which goes so far as providing them naval and air facilities. As a result, the Soviet Union now has a strategic position in the South China Sea it did not have previously, putting its forces uncomfortably near to the Straits of Molucca through which Middle East oil flows to Japan. Then there is the matter of Vietnam's presence in Cambodia and Laos, the former perhaps under tougher control than the latter.
Despite these obstacles, US diplomacy should not close the door to an overcoming of them. Hanoi recently ousted the hard-line communist party leader in the Cambodian capital of Phnom Penh, for instance, signal-ling perhaps that it wants to talk about resolving the Cambodia issue. Certainly the ASEAN countries, which themselves are wary of Chinese intentions in Southeast Asia, are eager for an improvement of US-Vietnamese ties as a counterweight to both Peking and Moscow. And, while they do not expect Vietnam to get out of Cambodia and Laos altogether, they believe Hanoi might accept some kind of neutral forces there.
How to get from A to Z is problematic, to be sure. But now that Hanoi has cracked open the door a bit, the US should be alert to testing the waters of accommodation on an official level and pursuing a flexible policy. Is Hanoi prepared to accept the American veterans' suggestion that it invite the US to send personnel to help in the search for the 2,500 servicemen still reported missing in Southeast Asia? However anguishing this might be for the Vietnamese, such a move would be reassuring to American public opinion.
Meantime, we are reminded again that even as searing and brutal an experience as war can begin to fade in the national consciousness and be replaced by civility. ''A couple of years ago I would have been given a medal for shooting some of the people I'm meeting with,'' commented one of the American veterans about the remarkable encounter in Hanoi. ''It blows my mind. What a crazy world this is.''
No one can fail to appreciate the sentiment.