Ruling Backs U.S. Forces’ Police Role : Law enforcement: Legal opinion supports overseas arrests. Drug traffickers, terrorists would be targets.

U.S. military forces have the legal authority to conduct law enforcement operations outside the United States, including pursuing and apprehending international terrorists and drug traffickers, Atty. Gen. Dick Thornburgh’s top legal adviser has ruled.

In a Nov. 3 memorandum that opens the door to direct participation by the military in stepped-up offensives in other nations, Assistant Atty. Gen. William P. Barr concluded that a Reconstruction Era ban on such involvement was not intended to apply outside U.S. borders.

Barr’s ruling, first reported Saturday by the Washington Post and confirmed by Administration sources, was made after questions were raised about the military’s authority to arrest Panamanian strongman Manuel A. Noriega if a coup attempt against him were successful.

Although the 28-page legal opinion cleared the way for such action, Administration officials emphasized that a policy decision “at the highest inter-agency levels” would be required before the military embarked on any law enforcement mission in other countries.

“Even though we may have the legal right to do some things, we may not--for political reasons--want to exercise all those rights,” a senior Defense Department official said.

Asked whether the Barr opinion had led to specific military actions, such as in the escalating offensive against South American cocaine traffickers, one Administration source declined to comment, while another said: “Not to my knowledge.”

The ruling could remove potential obstacles to the involvement of U.S. military forces in the escalating offensive against cocaine producers and traffickers in the South American nations of Colombia, Peru and Bolivia.

U.S. troops have been deployed to South America to work with local officials as part of an “Andean initiative” contained in President Bush’s anti-drug program, but their ability to apprehend traffickers was not clearly established until Barr’s opinion was issued.

However, any direct involvement by U.S. military personnel in the drug-producing nations would be certain to provoke significant nationalist opposition within those countries by citizens who view the U.S. involvement with suspicion.

The memorandum on law enforcement actions by military personnel addresses a different legal question than a controversial June 21 opinion by Barr that said the FBI had authority to seize fugitives overseas without obtaining permission of the foreign government.

And the assurances made by Administration officials that military actions would not be undertaken without prior approval at high levels illustrates their sensitivity to congressional criticism of the earlier opinion.

The Justice Department declined to make public Barr’s latest ruling, just as it had the June 21 opinion, on grounds that the documents constitute “private communications” between Barr and his “client”--Thornburgh, and, through him, President Bush.

But an Administration official said Barr’s latest written ruling was in line with a verbal opinion that his office of legal counsel had formulated during the Ronald Reagan Administration before Barr joined the government.

“OLC looked at the issue and wrote a rough first draft, but the issue abated,” and the opinion was never completed, an Administration official said. He declined to explain the facts under consideration at that time, but he said the verbal opinion did not lead to any action by the military.

Barr’s opinion reviews the history of the 1878 Posse Comitatus Act, passed in response to opposition to military oversight of Reconstruction Era elections. The ruling concludes that the act sought to bar military interference in functions of the states and was not meant to address military actions in other countries, an Administration official said.

“All the legislative history (of the act) related to interference with the states, with the military in conflict with Americans that could undermine confidence in the military,” he said. “It was not Congress’ intent for it to apply extraterritorially.”

Until recent years, the Pentagon had avoided any involvement in the fight against drugs entering the United States by citing the ban on military involvement in civilian law enforcement. But during the Reagan Administration, the act was amended to permit the use of the military for intelligence in drug interception along U.S. borders.

Defense Secretary Dick Cheney has invited proposals for broader military involvement in anti-drug efforts, and he has been considering initiatives submitted by the 10 principal U.S. military field commanders.

Several of these proposals “pushed the envelope on what we could or could not do” in fighting drug trafficking, a senior Pentagon official said. He added that Cheney has rejected some of the proposals on grounds that they went too far.

Doubts over the military’s limited powers in battling drugs were raised during the Noriega coup attempt. Gen. Maxwell Thurman, commander of U.S. forces in Panama, felt it necessary to have a federal law enforcement agent standing by in case the coup succeeded and Noriega could be arrested on federal narcotics charges he faces in Florida.

The White House then sought clarification of the limitations, which resulted in Barr’s opinion, an Administration source said.

Staff writer Melissa Healy contributed to this story.