President Harry Truman twice considered threatening the Soviet Union and China with "all out war" in an effort to end the Korean conflict, according to a handwritten journal Truman kept while in the White House.

The journal does not make any specific reference to nuclear weapons, though it says the communist countries would be "completely destroyed."

In an entry dated Jan. 27, 1952, Truman wrote that "the proper approach now would be an ultimatum . . . informing Moscow that we intend to blockade the China coast from the Korean border to Indochina" and that "if there is further interference we shall eliminate any ports or cities necessary to accomplish our peaceful purposes."

"This means all out war," the president wrote. "It means that Moscow, St. Petersburg [Leningrad], Vladivostok, Peking, Shanghai, Port Arthur, Dairen, Odessa, Stalingrad and every manufacturing plant in China and the Soviet Union will be eliminated.

"This is the final chance for the Soviet government to decide whether it desires to survive or not."

Senior military and State Department officials in the Truman administration now dismiss the threats, reported in the Houston Chronicle by Rice University historian Francis L. Loewenheim, as the musings of a president frustrated by the stalemated hostilities in Korea, and said the subject of a nuclear threat was never discussed in policy meetings during the period.

Charles Burton Marshall, a member of the State Department Policy Planning Staff at the time, said yesterday that the journal reflected Truman's "reveries."

"There's a bit of Walter Milty in all of us," he said.

Marshall said that the United States did not have the nuclear capability to carry out Truman's threat, even had it been considered seriously.

"The United States didn't have a great many capabilities it wasn't using at the time," he said.

Truman kept the journal from 1945 until 1952. It was among his personal papers, which have been kept in a private wing of the Truman library in Independence, Mo., and was inaccessible even to official archivists until recently.

Loewenheim called the journal entries "a kind of catharsis" for Truman, and said the journal apparently was never intended to become public.

In a later entry, dated May 18, 1952, Truman wrote a scathing denunciation of communist regimes.

"Dealing with the communist governments is like an honest man trying to deal with a numbers racket king or the head of a dope ring," he wrote. "The communist governments, the heads of numbers and dope rackets have no sense of honor and no normal code."

He accused the communist regimes of breaking "every agreement . . . made at Tehran, Yalta and Potsdam" and added. "Now do you want an end to hostilities in Korea or do you want China and Siberia destroyed?"

Two days before he wrote that entry, Truman told an Armed Forces Day dinner in Washington that for seven years since -- the time he authorized dropping the atomic bomb on Hiroshima -- "I have had but one object, to prevent a third world war -- and we are on the verge of success."

And two days after the entry, at a West Point convocation celebrating the academy's 150th anniversary, Truman said that the free world was winning its fight against aggression "without paying the frightful cost of world war." But he also warned against any let up in U.S. military production, saying the possibility of such a war had not become "remote."

Truman had a history of removing military officials who advocated aggression on the part of the United States. Navy Secretary Francis P. Matthews was ousted in 1950 after advocating preventive war in a speech in Boston. Maj. Gen. Orvil Anderson, commandant of the Air War College, was retired soon after that when he told a newspaper reporter that the Air Force only awaited orders to bomb Moscow.

Gen. Douglas MacArthur, then commander in the Far East, was dismissed in April 1951 after a celebrated disagreement with Truman over the general's strategy in Korea, which Truman feared would lead to war between the United States and China.

MacArthur, former aide Marshall noted yesterday, "did not have acute clearance and didn't know what our nuclear possibilities were."

In the final analysis, Marshall said, Truman's public policies, and not his private beliefs, guided the nation through the Korean war.

"A president is responsible for his actions," he said, "not his fantasies."