The Bush Administration stressed four legal justifications Wednesday for its invasion of Panama: the protection of American lives, the defense of the Panama Canal, the backing of the nation's "democratically elected" officials and the pursuit of an indicted U.S. drug criminal--namely, Manuel A. Noriega.
International law experts said the first reason is the strongest and the last the weakest.
"I think they can make a much more plausible case for this than the invasion of Grenada (in 1983) or the Dominican Republic in the '60s," said American University law professor Robert K. Goldman.
Because thousands of Americans are scattered around Panama and Noriega's troops have shown a willingness to harass and even kill them, President Bush had reason to use military force to protect them, Goldman said.
By contrast, the Reagan Administration justified its invasion of Grenada by pointing to the danger faced by a small group of American medical students, a rationale that was rebutted by international law bodies. Critics noted that the students could have been evacuated without U.S. troops overthrowing Grenada's government.
Under the norms of international law, nations are justified in using military force abroad to defend their citizens from hostile military action. But the response also must be limited to the amount of force necessary to protect the citizens.
The classic example of such a military move, law experts said, was the 1976 Israel raid on the Ugandan air base of Entebbe. Landing there, Israel commandos rescued their citizens who had been held hostage and then left, without attacking Ugandan dictator Idi Amin.
Several law experts, while agreeing on the need to defend American lives in Panama, questioned whether a full-scale invasion is justified under international law.
"When you have the killing of a Marine and the beating of the Navy man, some response was certainly called for," said USC law professor Edwin Smith. "Whether it rises to the level of a threat to U.S. sovereign interests is another question."
Columbia University professor Oscar Schachter said U.S. officials must show that the attacks on Americans were more than isolated incidents.
"I think they need to make a much stronger factual case than they have made so far," Schachter said. "If you have one man killed, you are not justified in bombing cities or killing lots of others. But if you can show a pattern of attacks, then you have a much stronger case. I don't think we know enough at this point to make a judgment."
Noriega and his few remaining allies would be hard-pressed to argue against the U.S. invasion in an international legal body such as the United Nations, the experts said, because he declared last weekend that his forces were in "a state of war" with the United States.
"That was his biggest blunder," Goldman said. "He badly overplayed his hand."
Justice Department officials made it clear that they still see the pursuit of Noriega as a criminal case.
Staking out a new legal position last month, Justice Department lawyers said that U.S. military personnel can track down and apprehend drug traffickers abroad. In the past, U.S. law was understood to restrict the military from engaging in criminal law enforcement. But under their new interpretation, Administration lawyers said, that limitation applies only within the United States and not beyond its borders.
International law experts scoffed at that justification for the invasion.
"Can you imagine," Goldman asked, "how we would react if another nation asserted the right to have its military engage in surreptitious kidnapings of Americans in this country?"
Times staff writer Ronald J. Ostrow contributed to this report.