A new congressional report suggests there are some weaks spots in the U.S. and allied argument that British and French missiles should not be counted in the intermediate-range arms talks between the United States and the Soviet Union.

There are 162 of the missiles, and the report by the Congressional Research Service notes that the question of whether to count them is "a major obstacle" in the intermediate-range nuclear forces (INF) talks that began in 1981 in Geneva.

The Soviets argue that the British and French weapons are aimed at them and must be taken into account, along with the planned deployment of 572 new U.S. missiles in western Europe, in any agreement that purports to balance forces on the two sides.

The United States, NATO Britain and France all vigorously oppose this view. They argue that the British and French missiles are sovereign forces of last resort that are not under NATO command and are meant only to deter attack on Britain and France. Defending the rest of western Europe would be left to U.S. missiles, it is said.

The CRS report is meant to be a guide and does not draw any conclusions. It includes all the main points made by the West and even adds some that are often overlooked.

Yet its tone, as CRS staff members acknowledged, suggests at least that the issue has two sides. It also suggests that some of the western arguments may ignore formal obligations undertaken by Britain and France in both the basic North Atlantic alliance treaty of 1949 and the subsequent western European union agreement.

For example, citing many British documents, the report points out that all 64 of Britain's submarine-launched nuclear missiles "are assigned to NATO." Although they remain under national command during peace, the missiles "are placed under SACEUR," the supreme allied commander in Europe, "in time of emergency" and the missiles "are targeted in coordination with U.S. Strategic Air Command targeting plans."

The British have reserved the right to withhold use of their nuclear arsenal, the report points out. But so too, technically, has the United States, whose forces can be used in defense of NATO only on authority of the president.

The French forces--80 submarine-launched and 18 land-based missiles--are much more clearly designated to remain under national control in an emergency. France, under President Charles de Gaulle, withdrew from the military portion of the NATO alliance in 1966.

But France and Britain are both signers of the 12-nation NATO charter of 1949, and that treaty, CRS reports, "commits both Britain and France to come to the defense of the other signatories in a manner appropriate to the attack."

The author of the CRS report, senior specialist Charles R. Gellner, says that "no military organization existed at the time this treaty was concluded . . . , so whether France refuses to participate in NATO's military organization does not matter. The treaty is as binding on France as it is on all signatories."

The report notes that although President Reagan and other western leaders now describe the British and French weapons as "strategic" because they can strike the Soviet homeland, during U.S.-Soviet strategic arms limitation negotiations in the 1970s the West successfully fended off demands by the Soviets to count British and French forces by describing them as "theater," or regional, weapons.

In portions that tend to buttress western arguments, however, the report notes that, by any means of measuring, the Soviets have far more intermediate-range missiles and bombers in Europe than does the West.

And because 144 of the 162 British and French missiles are based on submarines, only a handful are likely to be at sea at the same time. Thus, they should not be equated with Soviet land-based SS20 missiles that are always ready to be launched, the report says.