Aside from an Olympic boycott and some Olympian rhetoric, Jimmy Carter's chief response to the turmoil in the Mideast has been to deploy a 21-ship naval task force to the Arabian Sea.

At first glance, that would appear to be a formidable deterrent to any further Soviet aggression or Iranian irresponsibility. A closer examination, however, reveals some serious deficiencies behind this display: the ships are beset with manpower and equipment shortages that could impair their combat ability.

The Navy's problems, so starkly illustrated in the Arabian Sea fleet, are not new. Here are some critical shortcomings:

The Navy's overall shortage of some 20,000 mechanics and technicians has forced 70-hour work weeks on some key personnel in the Arabian Sea task force. Their morale is hardly improved by the knowledge they could be working half as hard and making twice as much money if they were civilians.

The flotilla could be put together only by stripping the Mediterranean and Pacific fleets, leaving them at dangerously low levels of capability. The Navy has been compelled to keep many of its vessels, like the aircraft carrier Kitty Hawk, on sea duty far beyond the rotation schedule, further aggravating already severe morale problems.

Classified reports disclose equipment shortages in the special task force of everything from spare parts to missiles. One secret study warns that the F14s on our carriers would have to go into combat without full loads of missiles. Meanwhile, at Navy facilities throughout the world, mechanics are cannibalizing warplanes to build up spare-parts inventories.

The shortage of ships has existed since the Nixon-Ford years, when the Navy retired nearly half its existing fleet. The admirals' hopes for replacement warships were scuttled by budgetary restrictions. The decline continued under Carter, and the Navy now has just 531 ships.

What makes matters worse is that the Navy's importance has increased during the very period when its strength has declined. A recent Brookings Institution study found that the Navy was called upon in 177 of the 215 occasions on which the United States used military force between 1946 and 1975. "There nothing going on in the world right now that indicates we need less of the Navy," a Pentagon source told my associate Peter Grant. Indeed, the recent events in Iran and Afghanistan -- and Carter's chosen response -- illustrate dramatically the need to keep the Navy in combat readiness.

The Navy's problems cannot be laid entirely to budget-cutters in Congress and the White House. In fact, the Navy historically snares the pirate's share of Defense Department appropriations. Much of the problem is self-induced, a result of the admirals' obsession with an aggressive, "go-get'-em" strategy for carrying an all-out global conflict to the shores of the Soviet Union. Their plans for World War III have neglected the kind of limited military operations that they are more likely to be called upon to wage.

In hearing after hearing, Adm. Thomas Hayward, the chief of naval operations, has proclaimed that the Navy must "take the battle to the enemy" and destroy the Soviet fleet. But this strategy would bring an all-out response from Soviet air, surface and submarine forces.

To counter this, the admirals have used their money to buy blue chips -- the most expensive, technologically sophisticated ships they can build. A modern destroyer is the size of a World War II cruiser, while the new Aegis air-defense cruiser -- intended to be able to penetrate Soviet waters -- has a price tag of $820 million. For that money, the Navy could buy four guided-missile frigates, with less sophisticated gadgetry but more firepower.

The Navy's single-minded pursuit of high-technology hardware at ruinous expense has drawn much criticism in Congress and elsewhere in the Pentagon. Studies by the Congressional Budget Office have shot down the admirals' insistence that they must attack the Soviet fleet to protect world shipping lanes.

To fight the kind of war the admirals foresee, and also have the quantity of ships that could respond to less than total-war situations, would be financially impossible, Pentagon sources say. President Carter's 1981 budget encourages the admirals in their quest for expensive quality.

Meanwhile, the Soviet navy is expanding in just the direction that will give them the edge in the limited confrontations that are the likely battlegrounds of the next few decades.