The Reagan administration's failed effort to induce Panamanian leader Manuel Antonio Noriega to surrender power was riddled with blunders and miscalculations, according to a number of independent experts.

But while many of the experts found fault with the way the administration handled the negotiations, they had few ideas on what the United States can do now to achieve its goals of an apolitical military and restoring constitutional rule in Panama."We're in for the long haul," said Eva Loser of the Center for Strategic and International Studies.

To some experts, the United States looked both foolish and weak after Noriega refused last Wednesday to sign on to a U.S.-brokered package deal that called for his resignation in August and temporary departure from Panama while an election process took place.

"I think that what's happened is we've really seen the limits of U.S. intervention," said Douglas Bandow of the Cato Institute. "And despite the fact that we're a superpower, we would have trouble killing a fly."

Assistant Secretary of State Elliott Abrams defended the negotiations in a telephone interview, saying, "People critical of the negotiations criticized us when we were not negotiating. That's called politics." Abrams argued that the negotiations revealed America's good faith and Noriega's lack of it.

James Hackett, an associate at the Heritage Foundation, said that the administration's first mistake was in bringing drug smuggling indictments last February against Noriega.

"You don't go around indicting foreign presidents or rulers," said Hackett, a former foreign service officer who once served in Panama.

"It was a very unfortunate thing to try to do," he said. "The whole thing was handled poorly."

Douglas Bandow of the Cato Institute agreed that it's a "little crazy" to blame other countries for a U.S. drug problem.

Several of the experts were unable to recall any instance in which federal indictments were handed upagainst a foreign leader. The closest recent parallel to the Noriega case was the 1985 indictment and subsequent conviction of Norman Sanders, a former chief minister of the Turks and Caicos Islands, a British dependency in the Caribbean.

Abrams, in the interview on Friday, discounted criticism of the indictments. "The indictments drove Noriega crazy and gave us a terrific bargaining tool," Abrams said. "For negotiating purposes, they turned out to be useful," he added, suggesting that administration envoys would not have come as close to an agreement as they did without them.

Loser of the Center for Strategic and International Studies said that what started out as an internal Panamanian problem "snowballed into a bilateral problem."

Loser, who recently returned from a visit to Panama, said that the United States mistakenly "treated him (Noriega) like a two-bit tin horn dictator. That's not how you treat someone of that caliber."

Loser said that the United States "should maintain and tighten" existing economic sanctions against Panama. She said Noriega is being aided economically by the money being poured into the Panamanian economy by the 50,000 Americans living there, and she recommended a way be found to limit the amount of money spent by Americans from circulating in Panama.

Ambler Moss, a former ambassador to Panama, agreed with Loser that the United States should have joined with other Latin American countries in the attempt to negotiate a settlement.

"I think we missed a good bet all along by going it alone and becoming the principal actor unilaterally in somebody else's internal political crisis," he said.

Moss also said Secretary of State George P. Shultz may have been wrong in saying last Wednesday that the talks with Noriega had ended when the Panamanian leader backed out of a deal that his subordinates had negotiated.

Moss said that it was possible that the deal was vetoed by Noriega's subordinates who were worried that the deal did not protect their interests.

"After all, Noriega isn't the only bad apple in the barrel," Moss said. "A number of them, apparently, according to the indictments, have been engaged in the drug business. They may wonder where all this leaves them at the end of the day, and when there is a cleanup, they're going to be the ones that get cleaned up."