Another irony of history: Sept. 11-era laws aimed at keeping terrorists out of the United States have disqualified many Hmong refugees, the very people specially recognized by Congress for helping American troops in the Vietnam war.

Under provisions of the USA Patriot Act and the Real ID Act, the Hmong who fought alongside the Americans in the "secret war" against communists in Laos are considered terrorists and are therefore ineligible for asylum or green cards. These are laws from the same Congress that in 2000 passed a law easing the citizenship requirements for the Hmong in recognition of their Vietnam era efforts.

"Clearly, it's absurd that people who fought with us — people who have received special exemptions from the law precisely for that conduct — should be barred from coming to the U.S. as refugees as a result of that conduct," said Melanie Nezer, an attorney for the Hebrew Immigrant Aid Society, who is coordinating a working group aimed at changing the laws.

The Hmong began arriving in large numbers during the 1970s, in the aftermath of Vietnam, and there were about 170,000 in the U.S. as of the 2000 U.S. Census, with most settled in California, Minnesota and Wisconsin. A later wave of about 15,000 settled in this country in 2005.

The anti-terror restrictions, which have ensnared other groups as well, also bar people who provided "material support" to terrorist organizations. Last month the Bush administration announced it was granting waivers of that restriction to eight groups, but the Hmong was not among them.

In Thailand, a group of 153 Hmong refugees have been in limbo as they await resettlement from an immigration detention center in the northern town of Nong Khai. A few weeks ago, the Thai government aborted plans to send the Hmong back to neighboring Laos, after the men in the group resisted and U.N. and U.S. officials expressed concern about the planned deportation. The Hmong say they will be persecuted in Laos because of their Vietnam-era ties to the U.S. The Netherlands recently agreed to take 22 of the Hmong.

Xee Vang, of Menasha, Wis., said her brother-in-law, his wife and their eight children are among those at the detention center. Vang said that her brother-in-law, whom she declined to identify by name, had fought alongside the U.S. during the Vietnam War, then fled to the jungle.

"It's very emotionally draining and frightening to hear about him and his family," said Vang, who spoke on behalf of herself and her husband, Chou Vang. "My husband is taking it very hard."

She said they have given up hope that their relatives will be able to come to the United States.

"I think it's unfair and stopping a lot of people who are legitimate refugees, who have sided with the U.S.," Vang said of the U.S. restrictions.

Paul Rosenzweig, the Department of Homeland Security's acting assistant secretary for international affairs, said most Hmong families have members who actually took up arms and so would not be eligible for the material support waiver. He said the administration is working on legislation to ease the restriction on the Hmong and other groups, which it will propose to Congress.

"In general, the reason we like the Hmong is because Papa fought with us," Rosenzweig said in a telephone interview. "Almost by definition, if you're one of the Hmong who was subject to our positive thought in the first instance, you run afoul of the unintended consequence of the law change."

Rep. Jim Sensenbrenner, the Wisconsin Republican who was a main driving force behind both the Patriot Act and the Real ID Act as chairman of the House Judiciary Committee, declined an interview request. Through a spokesman, Rajesh Bharwani, he said: "The laws are fine. If the Department of Justice and other agencies are overstepping their bounds, then the courts will stop them."

Philip Smith, the Washington director of Lao Veterans of America, a Hmong advocacy group, said that the restrictions are preventing Hmong refugees from coming to the U.S. and making it difficult for those who are already here to obtain green cards, which establish permanent residency.

"Thousands of Hmong veterans and family members are threatened with potential deportation down the road," he said. "And there is a clear and present danger they cannot be naturalized in a timely manner."

Larry Yungk, senior resettlement officer for the U.N. High Commissioner for Refugees, said that traditionally, 95 percent of the Hmong have come to the United States. Because of the restrictions, Australia and New Zealand have become two of the chief countries accepting them now, he said.

Momentum is building in Congress to change the restrictions. Sen. Patrick Leahy, D-Vt., the new chairman of the Senate Judiciary Committee, said in a statement: "We can protect national security, provide discretion to the administration, and at the same time fix the law so it can be applied predictably, fairly and in a timely manner. By doing so we will bring our laws back in line with our values."

Last year, Leahy and Sen. Norm Coleman, R-Minn., unsuccessfully tried to get an appropriations bill amended to change the restrictions. Coleman said he would continue to seek a legislative fix.

"Hmong refugees, who dedicated their service to America during the Vietnam War, have looked to the U.S. as a place of hope and a sanctuary from persecution," he said in a statement.

Naomi Steinberg, deputy director of the Southeast Asia Resource Action Center, said the restrictions have had a "devastating" impact on the Hmong community.

"Their history and their connection to this country is so strong," she said, "that their exclusion is mind-boggling and inhumane."