Sometimes, from inside the Pentagon, even Congress can look like the enemy.

Or so it seemed a few months ago to a senior Army attorney who wrote an internal memo accusing the staffs of Sen. Patrick J. Leahy (D-Vt.) and Rep. Lane Evans (D-Ill.) of engaging in espionage.

Their alleged nefarious act? Funneling information to the International Committee of the Red Cross (ICRC) about the U.S. negotiating position on the use of laser weapons to blind people.

"In essence, the offices of Senator Leahy and Congressman Evans are being used by the International Committee of the Red Cross as a vehicle for intelligence collection against the United States with regard to ongoing negotiations," wrote W. Hays Parks, a special assistant to the Army's judge advocate general.

"My review of U.S. law leads me to conclude that the staffs of Senator Leahy and Congressman Lane have engaged in espionage in violation of 18 U.S. Code, sections 793 and 794," Parks added, misstating Evans's name.

Since the memo was first reported by the Boston Globe last week, senior Pentagon officials have been at pains to label it "an unfortunate mistake" and disassociate the Defense Department from it.

Parks himself withdrew the memo shortly after it was written in May, but not before it had come to the attention of Leahy's and Evans's aides, who regarded the document as a rather bizarre attempt to intimidate them.

The Pentagon, after years of resisting any limits on lasers, announced a ban last month on laser weapons designed to blind foes permanently -- although it will allow other lasers that incidentally could have the same effect.

U.S. officials in Vienna attending a United Nations conference to review the 1980 Convention on Conventional Weapons have instructions to support negotiations prohibiting international use of lasers intended to blind.

Parks is a member of the U.S. negotiating team, and Pentagon officials describe him as fully supportive of the new U.S. position. But he held different views last year when Leahy aide Tim Rieser and Evans aide Tom O'Donnell first sought him out for a briefing.

Then, ICRC officials were rallying international backing for a draft protocol that would ban using lasers to blind as inhumane. While more than two dozen countries had endorsed some kind of restriction, the United States was resisting. The Army was moving ahead with plans to begin limited production of its first soldier-portable laser weapon for use against night-vision goggles, binoculars and other optical devices.

As one of the Pentagon's point men on the issue, Parks had written memos asserting that the use of laser weapons to blind was consistent with the laws of war and defending the Army's new tactical laser weapon as both militarily necessary and more discriminate than rifles or other weapons.

After talking with ICRC officials, Rieser and O'Donnell had lunch in December with Parks and a State Department lawyer, Edward R. Cummings, to hear the administration's reasons for opposing limits on laser weapons.

Parks provided the legislative aides with Defense Department legal opinions on the use of lasers. He says he told Rieser that the "opinions were for his information only and were not to be shared with others because of the ongoing negotiations," but that Rieser forwarded the opinions to the ICRC's senior legal adviser, Louise Doswald-Beck.

A Senate source says Rieser never gave the memos to anyone but did summarize the U.S. arguments in a letter to Doswald-Beck seeking her response as an expert on the issue.

Essentially, the administration was insisting that any prohibition on use of lasers to blind was unwise because it could interfere with other combat uses of lasers (for example, targeting and range-finding) and leave U.S. soldiers vulnerable to war crimes prosecution even for incidental use of laser weapons.

Besides, trying to negotiate the laser issue would divert attention from U.S. efforts at the U.N. conference to impose restrictions on land mines, administration officials argued.

The ICRC attorney wrote back to Rieser, saying she had heard all the arguments before and answering them one by one, according to the Senate source, who asked not to be named.

Leahy and Evans, convinced the United States was missing an opportunity to limit the spread of lasers, started pressing the Clinton administration to reconsider its position. Several months later, when the two legislators requested more information on the laser issue, Parks was moved to draft his unusual memo.

"There is reason to believe," he wrote, that the questions being posed by Leahy and Evans had been prepared by the ICRC in the interest of collecting intelligence about the U.S. negotiating position. Parks recommended not answering the request.

If answers are given, he added, they should be stamped classified. "I am informed that this is not uncommon, and believe it will limit the ICRC's intelligence collection against the United States government," he wrote.

Parks formally withdrew the memo a week later, explaining in writing that it had been drafted in haste and "had not been fully coordinated."

In a statement last week, the Defense Department had this to say about the memo: "Everyone in the Pentagon, including its author, regrets it was ever written."