A 1982 law that allows state courts to divide military retirement benefits as marital property in divorce proceedings has grown skin of armor, impenetrable to court challenge or legislative change.

That, at least, is how it must seem to longtime critics of the Uniformed Services Former Spouses Protection Act and to bureaucrats seeking changes just to improve how the law is administered.

Last month, a federal appeals court rejected a host of constitutional challenges to the USFSPA brought by 58 divorced retirees and active-duty members. Also last month, Congress would not allow the first minor adjustments to the ex-spouse law in 14 years, shelving three Senate-passed provisions. The reason: Lawmakers were peppered with complaints from divorced members and ex-spouses, some saying more should be done to ease their grievances and others wanting the law to be left alone.

"There is still power going through the third rail," said a congressional staff member of the wave of complaints, comparing the political hassle of amending the USFSPA to the deadly "third rail" that lawmakers believe they touch when they try to change the Social Security program.

Divorced members who continue to challenge the legality of the USFSPA in court suffered their latest disappointment Sept. 18 when the U.S. Court of Appeals for the 4th Circuit, in Richmond, Va., ruled in the Adkins v. Rumsfeld case.

The three-judge panel upheld a District Court judge's rejection of the lawsuit, examining the various constitutional challenges raised and finding none has merit. The plaintiffs in this case raised money for their legal challenge through a limited liability corporation they established called the USFSPA Legal Support Group.

Their lawsuit argues that the ex-spouse law violates divorced service members' rights to due process and equal protection. People who joined the military before the law was enacted should be protected from its effect because they served expecting to receive full retirement pay, plaintiffs argued.

Also, the lawsuit contends, states don't apply the law uniformly, which steps on Congress' authority "to raise and support armies." Plaintiffs also claim the law is discriminatory toward female service members. Their reasoning is that the law was enacted so that ex-spouses are not left destitute after military marriages dissolve. Yet the 24-year-old law fails to recognize the number of women now in service, and the reality that their male ex-spouses are more likely to have independent incomes.

Writing for the Appeals Court majority opinion, Judge M. Blane Michael considered and dismissed each arguments. It is incorrect to allege that before the USFSPA was enacted, Michael wrote, that Congress had promised to shield military retirement from valid court orders. Some states were dividing retired pay until 1981 when the Supreme Court ruled that such division was not backed by law.