Some 4,000 "Amerasian" children born of American GI fathers and Thai mothers are in danger of being made stateless by a local law intended to prevent Vietnamese refugees from becoming Thai citizens.

The law, imposed in 1972, has recently been reinterpreted to include those children whose GI fathers have deserted them and their mothers in Thailand.

Because the United States will not grant the children citizenship without their fathers claiming them and proving their parenthood, the children are effectively made stateless.

What this means, is addition to their not being entitled to passports and therefore not being able to leave Thailand, is that they will be denied Thai identity cards, entry into universities, military academies and the armed services, civil service jobs and land ownership.

"Unless this law is revoked, our kids will be crippled for life," said Robert M. Hearn, resident director, of the Pearl S. Buck Foundation in Bangkok. "We've seen it happen in South Korea and we know how children whose national loyalty can't possibly be questioned can be ruined."

Thai nationality is passed to children by their fathers. The law states, in part, that Thai nationality is to be withdrawn "from those persons born in the Kingdom of Thailand by alien fathers or by alien mothers, but without apparent legal fathers and at that time fathers or mothers were . . . persons who were allowed to reside in the Kingdom of Thailand temporarily."

At the height of the Vietnam war, 50,000 GIs were based in Thailand.

According to one interpretation, the intentions of the law, imposed by former dictator Thanom Kittikachorn, was to prevent children of Vietnamese refugees, whose loyalty could be questioned and who were considered potential security risks, from gaining Thai citizenship.

Charin Kanchanomai, director of the registration division of the local administration department, said the law, known as Announcement 337, "was not intended to be used only against Vietnamese children, but it was to be applied against any aliens."

Charin said the law has been used against the so-called Amerasian children since it took effect five years ago. A Thai newspaper, Khemtit, reported that in May the Interior Ministry ordered district officers to apply the regulation to children with an alien parent whose birth registration listed them as Thais.

Noting that this definition would include the children of some 500,000 hill tribespeople and unknown numbers of illegal immigrants. Charin said in an interview, "so you can see that it is not intended to single out the Amerasian children at all."

He explained that the birth registration forms contained a small box for "nationality." In those cases where "Thai" had been written in and the father of the child was found to be foreign, he added, "the word 'Thai' is scratched out and 'not Thai' is written in."

Since the issue of the Amerasian children was made public a few weeks ago, the pre-American military government has announced that "the matter will be reviewed as quickly as possible" and that "children born in Thai mothers ought to be entitled to Thai citizenship."

Hearn said he has seen registration forms showing fathers' names like "Mr. Jim" or "Sgt. Bob." According to other reports, in some cases nationality of the children is given as American.

"The district officials put down anything the mothers tell them," Hearn said, "and so they seal the fates of these kids for life."

According to Hearn, who has represented the Pearl S. Buck Foundation here for 10 years, "The Thai government has turned the whole matter of these kids over to us. Many of them look like Thais, all of them speak Thai and consider themselves Thais, but the government doesn't treat them like real Thais."

The foundation was established in 1964 by the late Nobel Prize-winning author and humanitarian Pearl S. Buck. In cares for 1,200 of the 4,000 or so Amerasian children in Thailand and has similar programs in the Philippines, Taiwan, South Korea and Okinawa.

Funded entirely by private donations from the United States, the foundation helps the abandoned Thai mothers or adoptive families to support the children. An estimated 90 per cent of the children were born out of wedlock.

Recently, U.S. Ambassador Charles A. Whitehouse expressed the "hope and belief" that Thailand would not reject the Amerasian children.