The President told Congress today that "it is not possible at this time to predict" how long the Panama operation might last.

The Panama operation also stirred concern in the United States military over the surprisingly high casualty rate among special operations forces, small clandestine units designed for commando-type operations.

Different From Grenada Although the Panama operation will be invariably compared to Grenada, it is misleading to make many comparisons.

Senator Nunn said the Panama operation had two clear lessons: the need for better intelligence gathering and the usefulness of lighter weapons.

Mr. Bush declared the military phase of the Panama operation "pretty well wrapped up."

In Washington, a new note of hesitancy crept into what had been a largely positive Congressional reaction, as lawmakers began to express concerns over how long the Panama operation would last.

The public was overwhelmingly behind the Panama operation, but now it's a sensitive subject, like Vietnam.

"It may be that there was too much emphasis put on snatching Noriega" in early Administration statements on the Panama operation, one senior official said.

"The conjunction of the premature disclosures and the Panama operation made it difficult for Barco to go along with it," a State Department official said.