"THREE TACTICAL A-BOMBS, properly deployed," Pentagon specialists estimated, would have to be dropped.

One "new weapon" might suffice for its explosive and "psycho effect," it was suggested more modestly by the National Security Council's Planning Board. "Could one 'new weapon' be loaned to France for this purpose? Could French airmen make a proper drop? Would French government dare take step?"

If the United States approached France on such a venture, an alarmed State Department official warned, "the story would certainly leak" and "cause a great hue and cry throughout the parliaments of the free world . . ."

The time was April l954. In a rain- shrouded valley of North Vietnam, an elaborate trap baited to catch the forces of Ho Chi Minh had snapped shut instead on the French Expeditionary Corps.

Dienbienphu had been buoyantly described by Gen. Henri Navarre, commander-in-chief of French Union troops, as "a veritable jungle Verdun," to lure the Vietminh to a killing ground. Gen. Vo Nguyen Giap had reversed the roles. Giap's artillery turned isolated Dienbienphu into a bloody chopping block for the French, in the decisive battle of the French Indochina war. The only hope for the beleaguered French was relief by outside forces, notably the United States, which was supplying prime financial support for France in the conflict.

For a generation, historians have debated how close the United States came to entering the Indochina war in 1954, to forestall the threat of "falling dominoes" throughout Southeast Asia. The result, of course, is well known: The United States did not intervene.

But declassified documents now confirm that the United States seriously considered everything from covert to overt intervention, with weapons ranging from conventional armament to atomic bombs. During the spring and summer of 1954, the Eisenhower administration was forced to weigh not only the costs and consequences of action and inaction in Vietnam. The crisis became a crucible for thinking through the American role in the world.

What is now available for the first time is the most extensive record ever made public, State Department historians say, on American decision-making during a prolonged crisis. There are 2,497 pages of documents, most previously unpublished. (Foreign Relations of the United States, 1952-54, Vol. XIII, Indochina, in two parts; Government Printing Office, $35. A small portion of the documents appeared in the Pentagon Papers in 1971.)

This record is a mine of information on the roots of American involvement in Indochina. It shows Eisenhower, not Secretary of State John Foster Dulles, as the decisive figure in shaping American policy.

Here is an Eisenhower the public rarely saw: combative, wry, sometimes angry, maneuvering against advisers inside the National Security Council who were either more hawkish or more dovish than he was. Some wanted to abandon Indochina entirely; others wanted to plunge in unilaterally and take over the war from the French, even if that meant a break with France, Great Britain and other allies.

In one tense NSC meeting on April 29, 1954, Eisenhower challengingly told his most militant-minded associates that he believed "if the United States were to intervene in Indochina alone, it would mean a general war with China and perhaps with the USSR, which the United States would have to prosecute separated from its allies."

"Without allies and associates," Eisenhower said, "the leader is just an adventurer like Genghis Khan."

Before he could bring himself to make a decision on unilateral intervention in Indochina, Eisenhower said, in the words of the note-taker, "He would want to ask himself and all his wisest advisers whether the right decision was not rather to launch a world war."

"If our allies were going to fall away in any case," the president continued, "it might be better for the United States to leap over the smaller obstacles and hit the biggest one with all the power we had. Otherwise we seemed to be merely playing the enemy's game -- getting ourselves involved in brushfire wars in Burma, Afghanistan, and God knows where."

In that sequence Eisenhower was debating, oddly enough, with Harold E. Stassen, then director of foreign aid. At an earlier meeting with Republican members of Congress, Sen. Eugene D. Millikin of Colorado suggested that "If our allies deserted, we would have to go back to fortress America."

Notes taken by press secretary James C. Hagerty show that the "president angrily ended the discussion by saying, 'Listen, Gene, if we ever come back to fortress America, then the word 'fortress' will be entirely wrong in this day and age."

"Dienbienphu," the president continued, "is a perfect example of a fortress. The Reds are surrounding it and crowding back the French into a position where they have to surrender or die. If we ever came back to the fortress idea for America, we would have . . . one simple, dreadful alternative -- we would have to explore an attack with everything we have. What a terrible decision that would be to make."

At the opposite end of the spectrum, others, notably Adm. Arthur W. Radford, chairman of the Joint Chiefs of Staff, raised the possibility of using nuclear weapons to save the French at Dienbienphu. Radford, who first proposed launching planes from aircraft carriers to attack the encircling Vietminh troops, had a larger objective than the rescue of the French garrison, according to the documents: crossing the threshold on the use of atomic bombs. That could have paved the way to employ nuclear weapons against China, Radford's ultimate target.

Dulles, speaking about nuclear weapons at a restricted meeting of North Atlantic Treaty Organization foreign ministers later that month, said, "Such weapons must now be treated as in fact having become conventional."

Long after Dienbienphu and the Geneva conference on Indochina, when Dulles was talking with associates about possible military action under the Southeast Asia Treaty Organization, which he formulated, minutes of a meeting on Oct 4, l954 show:

". . . the secretary stated that, in case of an all-out Vietminh attack, he foresaw American bombing of Tonkin and probably general war with China. Our concept envisions a fight with nuclear weapons rather than the commitment of ground forces . . ."

Heavy reliance on nuclear weapons was at the core of the so-called Dulles Doctrine of "massive retaliation," employing "brinkmanship" to stare down adversaries with American nuclear might. The Eisenhower administration came to office with a campaign that flayed the Democrats for "losing China" and stumbling into war in Korea. The administration claimed that its threat of widening that war produced the armistice which ended it in July 1953 (a claim still in dispute among historians).

It became a Republican imperative, therefore, to avoid blame either for "losing Indochina" -- in which the Truman administration first backed France against the Vietminh communists supplied by China and the Soviet Union -- or turning Indochina into an American war.

By early l954, the authorized American cost for supporting the French in Indochina that year was more than $1 billion, on the strength of Gen. Navarre's predictions of victory. The National Security Council was told on Jan. 8 that the French garrison of 10 battalions at Dienbienphu, near the Laotian border, already was surrounded by three Vietnminh divisions.

Adm. Radford reported that Gen. Navarre told him the Vietminh might well be able to overwhelm the position if they could accept heavy losses; Radford believed the Vietminh would avoid an all-out assault. If worst came to worst, Radford said, the United States could send an aircraft carrier to help the French hold Dienbienphu.

An NSC study cautioned that the French might pull out of the war -- by negotiating for a coalition government -- unless the United States committed forces to it. That "would eventually turn the country over to Ho Chi Minh," the study warned. Eisenhower "said with great force, he simply could not imagine the United States putting ground forces into Southeast Asia, except possibly Malaysia. . . Indeed, the key to winning this war was to get the Vietnamese to fight."

Public apprehension began to rise in early February when the Eisenhower administration sent 200 Air Force technicians and mechanics to Indonesia to augment the U.S. military mission. Nevertheless, Eisenhower reassured the nation on Feb. 10: "I cannot conceive of a greater tragedy for America than to get heavily involved now in an all-out war in any of those regions."

Dienbienphu demolished the administration's public projection of a successful, bloodless American investment in thwarting communism in Asia. Within hours after the first assault March 13, the Vietminh broke through the outer ring of fortifications in what became a 56-day seige.

For France, Dienbienphu loomed as the end of the line after seven years of war and a century of French rule in Indochina. For the Eisenhower administration it was a wholly new disaster, undermining its entire policy for thwarting communist expansion, with consequences out of all proportion to a battle involving 13,200 French Union troops and 49,500 Vietminh.

It was the American contention that the central problem in Indochina was France's strategy; especially its denial of real independence, and failure to train the Vietnamese to fight the war themselves, or to permit Americans to train them (the forerunner of the term "Vietnamization," when Vietnam became the American war of the 1960s and 1970s).

Gen. Paul Ely, chairman of the French chiefs of staff, arriving in Washington March 20, put the odds on holding Dienbienphu at "50-50." Others on the scene considered the cause hopeless. Ely asked for emergency aid, notably more B-26 bombers for the French. But his major request was for American air intervention if China sent its Mig jets into the battle.

Ely also had considerably more than that in mind. According to French sources, it was in Saigon that the American and French military together evolved the idea of "Operation Vulture": attacking the Vietminh at Dienbienphu with some sixty B-29 heavy bombers from the American base at Clark Field, near Manila, escorted by l50 fighters from aircraft carriers of the U.S. 7th Fleet.

The term "Operation Vulture" turns up in many contradictory forms in memoirs and histories on Vietnam. Radford said he knew of no plan by that name. But Ely returned to Paris saying Radford had given him personal assurance that if the Dienbienphu situation required it, Radford "would do his best to obtain such help from U.S. government."

The offical record shows that Radford first proposed "to the secretary of defense, and/or the president, that an immediate offer of assistance by U.S. Naval Air and/or Air Force units be made to the French, to assist in the defense of Dienbienphu."

Radford, however, could not carry his fellow chiefs of staff with him in crossing the non-intervention barrier. His own report of a March 30 meeting stated: "The individual service chiefs and the commandant of the Marine Corps unanimously recommended against such an offer at this time. The chairman (Radford) is of the opinion that such an offer should be made." (Air Force Chief of Staff Nathan F. Twining wrote that his actual position was "a qualified 'yes" -- with conditions; Radford listed that as "no.")

The strongest opponent was Army Chief of Staff Matthew B. Ridgway. The Army's position was that even atomic weapons would not bring victory, and that effective American intervention would require seven to 12 divisions, plus air support.

Radford's proposal brought a ferment of debate, a search for alternatives, and recriminations about France, with fears, especially by Dulles, that France might "sell out" to the communists in negotiations due to start in Geneva in May.

Dulles suggested to Eisenhower that "it might be preferable to slow up the Chinese communists in Southeast Asia by harassing tactics from Formosa (Taiwan) and along the seacoast . . ." Richard M. Nixon's memoirs add that Eisenhower told congressional leaders that if the Dienbienphu situation became desperate enough, he would consider "diversionary tactics, possibly a landing by Chiang Kai-shek's Nationalist forces on China's Hainan Island or a naval blockade of the Chinese mainland."

The president either toyed with secretly sending aircraft carriers "to bomb (the) Reds at Dienbienphu" -- or wanted others to think he might do so. He told two publishers at lunch on April 1 that "of course, if we did, we'd have to deny it forever."

Eisenhower, however, already had informed his National Security Council on March 25 that "the Congress would have to be in on any move by the United States to intervene in Indochina." Eisenhower, picking up on a suggestion from Stassen, proposed seeking united action by such nations as Britain, France, Australia, New Zealand, the Philippines, Formosa (Taiwan) and "the free nations of Southeast Asia."

Dulles floated the idea of "united action" on March 29, in an address entitled "The Threat of a Red Asia." The State Department quietly prepared a draft joint resolution, authorizing the president "to employ the naval and air forces of the United States to assist the forces which are resisting aggression in Southeast Asia . . ."

Here the tactics, as well as the strategy, were Eisenhower's. The "tactical procedure," he told Dulles, was "to develop first the thinking of congressional leaders" before deciding to unveil the resolution. That move came April 3 when Dulles, Radford and other officials called in eight members of Congress, including Senate Republican Majority Leader William F. Knowland and Senate Democratic Minority Leader Lyndon F. Johnson.

Historically, this meeting is doubly significant. For Johnson it was a preview of his own agonizing presidential decisions on committing troops to Vietnam a decade later.

Until now, historians have relied on an unofficial account of that encounter, entitled "The Day We Didn't Go to War," by Chalmers M. Roberts, then diplomatic reporter of The Washington Post, published in Reporter Magazine in September 1954. That reconstructed account said Radford gave the congressmen "the scare of their lives" with his proposal: Once Congress passed a joint resolution, the United States would send some 200 planes from the U.S. aircraft carriers Essex and Boxer, then in South China seas, plus land-based U.S. Air Force planes from the Philippines, on "a single strike" to save Dienbienphu.

Under questioning, that version of the meeting reported, Radford agreed the action would mean war, and that there would be other strikes if the first failed to relieve the garrison. When asked how many of the other Joint Chiefs agreed with his plan, Radford replied, "None." Radford's explanation was that he had spent more time in the Far East "and I understand the situation better."

Johnson, the Roberts account continued, pointedly said Knowland had been protesting that the United States put up 90 percent of the men and money for the Korean war. Therefore, Johnson said the United States should know first who would contribute troops to Indochina. That became the key. Could the United States get allies to join the intervention?

The official summary of that meeting from Dulles' files raises questions about the administration's candor with the congressmen, and it leaves unexplained why the original report of that meeting was revised two days later. One possible reason comes to mind: The originale rationale for possible U.S. intervention, to relieve the French garrison at Dienbienph, changed.

In contrast to all earlier versions of the sequence, the post-dated record of the meeting, dated April 5, reports that Radford told the congressmen there was no longer any hope for using American airpower to salvage Dienbienphu.

It "was too late," Radford is reported to have told Sen. Johnson and his colleagues; "if we had committed airpower three weeks ago, he (Radford) felt reasonably certain that the Red forces would have been defeated."

There is nothing in this official version about "a single strike" at Dienbienphu, as congressional sources related the discussion to Roberts. Instead, the official account refers only, without specifics, to Dulles urging the necessity to empower the president to "use air and seapower in the area if he felt it necessary in the interest of national security.(quote end here?) Radford did not disclose to the congressional delegation what subsequent documents show he was contemplating in Vietnam: atomic bombs.

The Dulles memorandum reported that he and Radford stated that the administration "did not now contemplate the commitment of land forces," but the wary congressmen "replied that once the flag was committed the use of land forces would inevitably follow."

The United States would have to get allies. There was "very little confidence in the French," and "less criticism of the British," but Sen. Richard Russell of Georgia said that "if the U.K. flinched in this matter, it would be necessary to reconsider our whole system of collective security . . ."

A record of a critical meeting in the president's "upstairs study" of the White House the night of April 4 shows the planning was extending far beyond Dienbienphu, which is not mentioned in the brief summary.

It says Eisenhower "agreed with Dulles and Radford on a plan to send American forces to Indochina under certain strict conditions":

"It was to be, first and most important, a joint action" with British, Australian, New Zealand, and possibly Philippine and Thai troops. France "would have to continue to fight in Indochina and bear a full share of responsibility until the war was over." Additionally, to avoid the perception that the United States was protecting "French colonialism," France would have to ""guarantee future independence" for Vietnam, Laos and Cambodia.

That same night France asked for a strike by U.S. aircraft carrier planes to support Dienbienpu. Eisenhower in a telephone conversation with Dulles next morning said that was impossible; in the absence of congressional support it would be "completely unconstitutional and indefensible."

Radford, meanwhile, had additional ideas about what was required. In a message relayed to Dulles on April 7, Radford said the Pentagon's Joint Advanced Study Group had "reached the conclusion that three tactical A-weapons, properly employed, would be sufficient to smash the Vietminh effort" at Dienbienphu.

That study, in turn, raised in Radford's mind the question of whether, once a coalition was established in Southeast Asia, "we could use atomic weapons on the Vietminh if this seemed the best means of smashing them and cleaning up Indochina."

If France would agree in principle, this would advance "the whole conception" of employing nuclear weapons.

The proposal evidently stunned State Department Counselor Douglas MacArthur II when he received it. He wrote that he believed the French would spurn it; "the story would certainly leak," arouse alarm "throughout the parliaments of the free world," and might bring pressure for assurances "that we would not use A-weapons without consultation."

By April 30, however, a variation was suggested by the National Security Council's Planning Board.

It asked: "Should decision be made now as to U.S. intention to use 'new weapons,' on intervention, in Vietnam on military targets? Would one 'new weapon' dropped on Vietminh troop concentrations behind DBP (Dienbienphu) be decisive in casualties and overwhelming in psycho effect on Vietminh opposition?" The study went on to ask if "one 'new weapon'" could be "loaned to France for this purpose," if French airmen could drop it properly, and would France "dare take step."

Richard M. Nixon, then vice president, referring in his memoirs to Radford's nuclear plan (describing it as "Operation Vulture"), said Eisenhower and Dulles "felt that nothing less than overt Chinese communist aggression would be sufficient provocation for our going into Vietnam in any such direct and unilateral way."

As for the NSC staff study on possible use of atomic weapons with allied intervention, Nixon told the president he saw no need "to mention it to our allies before we got them to agree on united action." Eisenhower turned to his special assistant for national security, Gen. Robert Cutler, Nixon wrote, and said: "First, I certainly do not think that the atom bomb can be used by the United States unilaterally, and second, I agree with Dick that we do not have to mention it to anybody before we get some agreement on united action."

How serious were Eisenhower administration leaders about using atomic bombs in Indochina under any circumstances?

Nixon wrote in his memoirs:

"The press perceived Dulles, Radford, and me as the hawks in the Indochina crisis. To some extent Radford did believe that the early use of tactical nuclear weapons would convince the communists that we meant business. Dulles and I both believed that if the communists pushed too far we would have to do whatever was necessary to stop them. Eisenhower fully agreed, although I think Dulles and I were probably prepared to stand up at an earlier point than he was. We all hoped that by being prepared to fight we would never actually have to do any fighting."

There is no evidence that the United States ever offered France atomic bombs, although French Foreign Minister Georges Bidault claimed that, and the story spread through the shocked French hierarchy -- and leaked.

Dulles' denial of Bidault's assertion was disclosed in the Pentagon Papers, but without what is now revealed, that the NSC's Planning Board did raise the question of "loaning" one atomic bomb to France. That undoubtedly would have been construed as giveing credibility to the Bidault claim.

The U.S. embassy in Paris informed Dulles Aug. 9, 1954, that Bidault said Dulles "made this offer to Bidault during a private discussion" in late April in Paris when Dulles was en route to the Geneva conference on Indochina. The French version was that "Bidault was very much upset about this offer and felt that the use of atomic bombs would have done no good tactically and would have lost all support for the West throughout Asia."

Dulles immediately replied that he was "totally mystified" by Bidault's account; could find no record of such a conversation, and found it "incredible that I should have made such an offer since thke law categorically forbids it.." He said Bidault may have mixed up Dulles' statement to NATO ministers April 23 that atomic bombs must now be treated as "conventional" weapons.

The U.S. ambassador in France, C. Douglas Dillon, told French officials "it was obvious that there had been a complete misunderstanding by Bidault, possibly based on language difficulties." Dillon reported that Bidault was in poor condition that day (Dienbienphu was nearing its end), and a senior French "agreed there must have been such a misunderstanding," for Bidault "had been jittery, overwrought," and "'incoherent' to members of his own top staff. Bidault's memoirs neverthless repeated the story, saying Dulles offered "two atomic bombs."

Dulles, as he subsequently acknowledged, was engaged in "brinkmanship" at the time, aimed at China and the Soviet Union. His goal and Eisenhower's, was to assemble a formidable-looking alliance to intimidate China, in particular, with the threat of a wider war, so as to induce it to back away from the Vietminh and reduce the communist bargaining hand in the Geneva conference.

But Britain was fearful, as Eisenhower administration officials expressed it, that any plan to send new forces to Indochina "might result in an all-out war with China, po ssibly involving the use of atomic weapons" and World War III. In a whirl of diplomatic bargaining, Dulles believed for a time that he had Britain's commitment to a new coalition, then charged that London reneged on it.

Britain joined France on putting its priority on seeking a negotiated end to the war Geneva before attempting a new alliance for Southeast Asia. The Eisenhower administration even briefly explored the possibility of forming such an alliance without either Britain or France, at the risk of shattering the Atlantic Alliance.

Dienbienphu fell on May 7, l954, the day before the opening of the Indochina phase of the Geneva conference. That is another chapter. It took France out of the war, but the United States edged its way deeper into it. American strategy, Dulles maintained, was not totally without success: communist demands at Geneva, he said, were moderated by fear of an "adverse reaction" and the threat of general war if they asked too much.

For the United States, Dulles said, the problem now was whether "we could salvage what the communists ostensibly left out of their grasp."