Against the military's better judgment, the Carter administration is continuing in slightly modified form a strategy that, kept secret from Japan, would "swing" substantial U.S. naval force from the western Pacific to Europe if the Soviets attacked NATO.

This confirms the "swing strategy," one of the U.S. government's most closely held secrets for 25 years. Plans to shift half of U.S. naval power to Europe professionals in two ways: first, it underlines U.S. naval weakness in coping with a global emergency; second, it is less than candid in dealing uith Japan (which, if it knew the truth, could be urged to step up its own defenses).

Nevertheless, continuation of the post-Korean War swing strategy was recommended by the Pentagon's Consolidated Guidance Study No. 8 (CG8) of May 14. It did urge that U.S. replies to NATO's annual defense planning questionnaires (DPQs) be amended to make more flexible just how many ships would "swing." But secrecy toward Tokyo was endorsed: "It is recommended that the U.S. not announce the DPQ commitment, whether modified or not, to its Asian allies."

This recommendation is grounded in the bleak assessment, quoted in the document, by the U.S. commander-in-chief, Pacific, of what would happen if half his fleet were sent to Europe: " . . . He would have to turn his back on U.S. alliance commitments and become totally defensive in order to survive in the Pacific."

High officials refer to documents such as CG8 as "think papers" when disclosed. In fact, not only are its recommendations secret U.S. policy, but it unwittingly says the unsayable by admitting U.S. global weakness. Without meaning to be, it is a chilling document.

Particularly unsettling is the counterpoint of comments by the military, peppered throughout, mostly as asterisks and parenthetical notes. For example, this footnote: "The joint staff believes we do not have sufficient assets to perform all missions assigned in a global war." The alternative "is to program additional forces."

Time and again, conclusions of CG8 (directed by Dr. Lynn E. Davis, a deputy assistant secretary of defense) are challenged by military professionals. A footnote from NATO commanders suggests the "swing" forces would arrive in Europe too late. A footnote from the Navy and the Defense Intelligence Agency disagrees with CG8'S "view" (attributed to the CIA) that the Soviets probably would not and could not interdict U.S. shipping to Europe.

In forwarding CG8 to Defense Secretary Harold Brown, Assistant Secretary David E. McGiffert noted that the Joint Chiefs of Staff "believe the long-term solution is to obtain the forces required to make the 'swing' unnecessary." Nevertheless, McGiffert called the military rationale for the swing strategy "sound."

What did trouble McGiffert, Davis and other authors of the document is what McGiffert flatly calls "subterfuge" in dealing with Japan. CG8 rejects the naval buildup favored by the Joint Chiefs and warns that "any U.S. initiative to retreat from the swing concept probably could be viewed in NATO capitals as . . . an indication of confusion and indecision among U.S. policy-makers."

Yet the document warns that "public acknowledgment" of the swing strategy could "further reinforce" Asian notions of a "general U.S. withdrawal from the region." Even though Japan and other U.S. allies in Asia "are probably aware" of the strategy, "public disclosure or official notification of our Asian allies . . . could further undermine the credibility of our commitments in Asia and become an issue in our defense relations with Japan." The backdrop: consternation over Carter's now modified withdrawal of U.S. ground forces from Korea.

Specifically, CG8 warns that a public discussion would "strengthen pressures for Japan to go neutral or rearm." Here is the issue between Carter appointees, such as Lynn Davis, and the professionals, both military and civilian, who think neutrality out of the question and want Japanese defense spending encouraged by telling Tokyo the truth. But Davis and her State Department allies are wary of Japanese military expansion.

This conflict leads to the flights from reality characteristic of Carter administration defense policy papers. Arguing for the swing strategy, the paper claims "a primary Japanese concern is whether she becomes directly involved" in a U.S.-Soviet conflict. "While Japan would undoubtedly be disturbed if the carriers on the [U.S.] West Coast headed for the Mediterranean rather than for [the western Pacific], she would be more disturbed if U.S. carriers . . . prepared to initiate attacks against Petropavlovsk, and these preparations resulted in preemptive Soviet attacks against U.S. bases in Japan."

Here is a family resemblance to Presidential Review Memorandum 10, which in 1977 envisioned withdrawal from one-third of Germany if the Soviets attack, and President Carter's Oct. 1 grudging acceptance of growing Soviet military power in Cuba. Being forced by weakness to deceive one ally to help another adds another chapter to U.S. decline.