One saving element from the U.S. standpoint is that the British naval force will not be able to do much when it arrives near the Falkland Islands unless Argentina allows it, several U.S. naval experts said yesterday.

The experts, in interviews, agreed that Britain would need control of the air and a much larger support force than it has dispatched in order to go to war in the southern Atlantic region.

Said one retired U.S. admiral long associated with North Atlantic Treaty Organization war planning: "The British made the decision to structure their navy to only certain NATO tasks and have lost their ability to conduct independent action in the process." The admiral said that the British relinquished the role of controlling the air over hostile beaches to American aircraft carriers during this restructuring process.

These military officials, because of the thinness of the British navy for distant action, predicted that the confrontation would be a series of subtle pressures rather than anything like an all-out invasion of the islands.

Marines, one admiral said, could be landed on a remote beach as a diplomatic ploy in hopes of advancing negotiations, but could not make a stand so far away from home without more support than the British have so far deployed. Similarly, said one admiral, the British do not have enough naval force to draw from to establish a successful blockade for any length of time.

"It will be just terribly difficult for the British to do anything in a military sense," contended one admiral.