The bad faith evident in communist Vietnam's handling of the inmates of its "reeducation camps" is striking. Hanoi, you will recall, had challenged the United States to take these people, who worked in the U.S.-backed Saigon government that fell in 1975 and who have since suffered severely on account of that tie. The Reagan administration suspected that Hanoi only wanted to distract critics accusing it of keeping political prisoners indefinitely in concentration camps. But to test the water, it offered last fall to admit up to 10,000 camp inmates and their dependents and it set out to make the necessary arrangements with the Vietnamese.

Two well-prepared congressional delegations visited Vietnam this month, one led by Rep. G. V. Montgomery (D-Miss.) and the other by Rep. Stephen Solarz (D-N.Y.). Both found the Vietnamese were injecting a provocative and disturbing new element into their talks with the United States -- a demand that the American government take on a formal obligation to subject the new immigrants to political restrictions different from and far tighter than the laws covering all other American immigrants and citizens.

Ostensibly Hanoi fears anti-regime ,emigr,e activity by "criminals." In fact, by insisting that the United States in effect replicate some of the very controls that Vietnam imposes in the "reeducation camps," and in its society at large, it seems simply to be trying to put the onus for the camp inmates' plight on Washington.

If this is so, then Hanoi should understand its tactics will not work. Americans, no matter how divided they were by the war, are joined in a readiness to meet the country's obligations to Vietnamese who cast their lot directly with the United States. On this issue, Hanoi will find no room for political manipulation. The camp inmates are welcome here as immigrants on the same terms applicable to everyone else. In Vietnam, the state imposes penalties and discriminations on individuals on the basis of its own uniform political tastes, but not in the United States.

The Vietnamese are in an especially unyielding mood these days. Not only are they toying with the camp inmates; they are also sending their occupation troops in Cambodia into refugee camps, inflicting heavy civilian casualties and driving tens of thousands of refugees into neighboring Thailand. Meanwhile, the visiting congressmen report, they are resisting the steps that might bring a negotiated Cambodian settlement within at least remote reach. Vietnam won the war in the 1970s, but its leadership -- bitter, vindictive, lacking vision -- continues to lose the peace. The Vietnamese people pay for it.