WASHINGTON - U.S. military leaders proposed in 1962 a secret plan to commit terrorist acts against Americans and blame Cuba to create a pretext for invasion and the ouster of Communist leader Fidel Castro, according to a new book about the National Security Agency.

"We could develop a Communist Cuban terror campaign in the Miami area, in other Florida cities and even in Washington," said one document reportedly prepared by the Joint Chiefs of Staff. "We could blow up a U.S. ship in Guantanamo Bay and blame Cuba," the document says. "Casualty lists in U.S. newspapers would cause a helpful wave of indignation."

The plan is laid out in documents signed by the five Joint Chiefs but never carried out, according to writer James Bamford in "Body of Secrets." The new history of the Fort Meade-based eavesdropping agency is being released today by Doubleday.

NSA regularly picks up the conversations of suspected terrorist financier Osama bin Laden, says Bamford, and has monitored Chinese and French companies trying to sell missiles to Iran. He provides new details about an Israeli attack on a Navy eavesdropping ship in 1967, suggesting that the sinking was deliberate. And he reveals the loss of an "entire warehouse" full of secret cryptographic gear to the North Vietnamese in 1975, at the end of the Vietnam War.

Bamford, a former investigative reporter for ABC News who wrote "The Puzzle Palace" about the NSA in 1982, said his new book is based mostly on documents obtained through the Freedom of Information Act or found in government archives. "NSA never handed me any documents," he said. "It was a question of digging."

He said he was most surprised by the anti-Cuba terror plan, code-named Operation Northwoods. It "may be the most corrupt plan ever created by the U.S. government," he writes.

The Northwoods plan also proposed that if the 1962 launch of John Glenn into orbit were to fail, resulting in the astronaut's death, the U.S. government would publicize fabricated evidence that Cuba had used electronic interference to sabotage the flight, the book says.

A previously secret document obtained by Bamford offers further suggestions for mayhem to be blamed on Cuba.

"We could sink a boatload of Cubans en route to Florida (real or simulated). ... We could foster attempts on lives of Cubans in the United States, even to the extent of wounding in instances to be widely publicized," the document says. Another idea was to shoot down a CIA plane designed to replicate a passenger flight and announce that Cuban forces shot it down.

Citing a White House document, Bamford writes that the idea of creating a pretext for the invasion of Cuba might have started with President Dwight D. Eisenhower in the last weeks of his administration, when the plan for an invasion by Cuban exiles trained in the United States was hatched. Carried out in April 1961, soon after Kennedy became president, the Bay of Pigs invasion proved a fiasco. Castro's forces quickly killed or rounded up the invaders.

Army Gen. Lyman L. Lemnitzer, chairman of the Joint Chiefs, presented the Operation Northwoods plan to Kennedy early in 1962, but the president rejected it that March because he wanted no overt U.S. military action against Cuba. Lemnitzer then sought unsuccessfully to destroy all evidence of the plan, according to Bamford.

Lemnitzer and those who served with him in 1962 as chiefs of the nation's military branches are dead. But two former top Kennedy administration officials said yesterday that they were unaware of Operation Northwoods and questioned whether such a plan was ever drafted.

"I've never heard of Operation Northwoods. Never heard of it and don't believe it," said Theodore Sorenson, Kennedy's White House special counsel. "Obviously, it would be totally illegal as well as totally unwise."

Robert S. McNamara, Kennedy's defense secretary, said: "I never heard of it. I can't believe the chiefs were talking about or engaged in what I would call CIA-type operations."

Bamford writes that besides the Joint Chiefs, then-Assistant Secretary of Defense Paul H. Nitze also favored "provoking a phony war with Cuba."

"There may be a piece of paper" on Northwoods, said McNamara. "I just cannot conceive of [Nitze] approving anything like that or doing it without talking to me."

The book contains many other revelations in its detailed account of NSA, the biggest U.S. intelligence agency and Maryland's largest employer, with more than 25,000 personnel at Fort Meade, site of its global eavesdropping efforts.

Among them:

In recent years, NSA has regularly listened to bin Laden's unencrypted telephone calls. Agency officials have sometimes played tapes of bin Laden talking to his mother to impress members of Congress and select visitors to the agency.

In the late 1990s, NSA tracked efforts by Chinese and French companies to sell missile technology to Iran, particularly the C-802 anti-ship missile. The eavesdropping led to U.S. protests to the Chinese and French governments.

When U.S. troops evacuated Vietnam in 1975, "an entire warehouse overflowing with NSA's most important cryptographic machines and other supersensitive code and cipher materials" was left behind. It was the largest compromise of such equipment in U.S. history, Bamford writes, but the agency still has not acknowledged it.

When Israeli fighter jets attacked the NSA eavesdropping ship USS Liberty in the Mediterranean in 1967, killing 34 Americans and wounding 171, an NSA aircraft was listening in and heard Israeli pilots referring to the American flag on the ship. U.S. officials, including President Lyndon Baines Johnson, decided to forget the matter, Bamford writes, because they did not want to embarrass Israel. To this day, Israeli officials say their forces mistakenly attacked the U.S. ship.

Bamford says the reason for the strike was Israel's desperate effort to cover up its attacks on the Egyptian town of El Arish in the Sinai. The Liberty was sitting offshore and the Israelis feared that the ship would detect the operation, which included the shooting of prisoners.

Yesterday, an NSA spokesperson questioned a point made in the book about the USS Liberty.

"We do not comment on operational matters, alleged or otherwise; however, Mr. Bamford's claim that the NSA leadership was `virtually unanimous in their belief that the attack was deliberate' is simply not true," the spokesperson said.

When he wrote "The Puzzle Palace" in 1982, Bamford was attacked by some NSA officials, who said his revelations gave the Soviet Union and other U.S. adversaries too much information on the secret agency. One former director referred to him as "an unconvicted felon."

With the end of the Cold War, the agency has been less guarded. NSA's current director, Air Force Lt. Gen. Michael V. Hayden, has granted a number of interviews. Hayden "cracked the door open a tiny bit," said Bamford, partly to burnish NSA's public image and correct misconceptions.

Sun staff writer Laura Sullivan contributed to this article.