The CIA obtained a gun and hired an assassin, but he refused to proceed when he found out who his target was

The other involved a staged gunfight at an anti-Vietnam War convention where Nixon was to speak, with an assassin shooting him in the chaos

One, quickly dismissed, was a plot to fire a missile at Nixon's vacation compound in Key Biscayne, Florida

Two separate plans were drawn up to kill him

The agencies wanted room to run in Vietnam but Nixon turned dovish and began a troop withdrawal after his stunning White House victory in 1968

CIA and military Joint Chiefs infiltrated the White House and spied on Nixon, the late former president's longtime confidant Roger Stone writes

The CIA plotted twice to assassinate President Richard Nixon during the years before the Watergate scandal because the agency was angered when 'Tricky Dick' turned dovish and began to withdraw troops from Vietnam, according to an explosive book from a longtime Nixon confidant due for release on Monday.

One hit was planned to occur at Nixon's Key Biscayne, Florida vacation house. A second plot to kill him was to culminate during a Miami speech in 1972.

When both plots failed, writes best-selling author Roger Stone in 'Nixon's Secrets: The Rise, Fall and Untold Truth about the President, Watergate, and the Pardon,' the CIA settled for driving Nixon out of office by sabotaging the Watergate break-in.

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Richard Nixon was lucky to survive long enough to resign, judging from claims in a new book that describes two separate CIA plots to assassinate him

Controversial: Roger Stone's last book claimed President Lyndon Johnson was behind the JFK assassination

'I first learned about this from Howard Liebengood,' Stone told MailOnline on Wednesday, referring to the Republicans' minority counsel to the Senate Watergate Committee in the 1970s.

'The president was supposed to be assassinated,' he quotes Liebengood saying in his book. 'The first place he was supposed to be assassinated at was in Key Biscayne, the second place was when he was supposed to give a speech at the time of the Vietnam Veterans Against the War [VVAW] convention in Miami Beach 1972.'

'Veteran CIA assassin Edwin Kaiser was to supply the weapons to assassinate Nixon with.'

Kaiser, an anti-Castro revolutionary, had killed for the CIA before, but Stone claims he and fellow CIA contract killer Frank Sturgis backed out of the mission when they learned who they were expected to kill.

Stone said he obtained Kaiser's papers from his son Scott, who has his own book in the works. 'Edwin Kaiser's Covert Life: And His Little Black Book Linking Cuba, Watergate & the JFK Assassination,' will be published in October.

'I got confirmation from Kaiser's papers,' he told MailOnline.

Stone claims in his book that Liebengood, who died in 2005, told him that Kaiser and Sturgis 'both insisted that they had not been informed that Richard Nixon was the target until after the intended weapon was obtained.'

'Both Sturgis and Kaiser insisted they had been led to believe that they were to execute a "Communist"' at the VVAW convention, he writes that Liebengood told him. 'Kaiser balked when he realized it was a domestic political hit.'

'Nixon's secrets' is due on bookshelves August 11 and promises to shake up the historical understanding of the only US president to resign his office

He went to the FBI in Miami instead and the plot fizzled.

Stone's claims are documented in part by an email from Scott Kaiser in which the assassin's son writes that his father had recalled talking to the CIA's plotters.The idea was to 'create a shoot-out using the Yippies and the Zippies' – anti-war student radical groups – 'and the other "hard core commies" they were so worried about,' he said his father had explained.

'The people I spoke to were going to put some of this equipment in their hands,' the elder Kaiser had said, according to his son's email reproduced in Stone's book, 'and some in law enforcement hands, and use some of the local vigilantes to start a shoot out.'

'This would finally straighten out Washington as to where the priorities were on overcoming the "domestic communist menace".'

The planned diversion wasn't the CIA's first plot to rub out Nixon, Stone claims.

In the email he publishes in 'Nixon's Secrets,' Scott Kaiser wrote that a CIA operative named Gerald Patrick Hemming told his father how associates of Antonio Veciana, a Cuban emigre who had been involved in a CIA-led – and Nixon-approved – plot to kill Fidel Castro, 'had a scheme to ... [fire a] missile at the compound' in Key Biscayne where the president was staying.

'They were gonna take out Nixon and put Agnew in power,' Hemming concluded, suggesting that the CIA was also involved in that conspiracy.

Some of the same CIA operatives involved in the Nixon assassination plots – including Kaiser, Sturgis and Hemming – were later planted among the Watergate burglars, Stone explains in 'Nixon's Secrets.'

(For the conspiracy-minded, 'Nixon's Secrets' also notes that Hemming had been JFK assassin Lee Harvey Oswald's case officer at a naval air station in Japan, a point of origin for top-secret U-2 spy plane flights.)

The CIA, he claims, inserted its own people among Nixon's 'plumbers' over time with instructions to make rookie mistake after rookie mistake.

CIA theory: Stone says many of the Watergate burglars including Virgilio Gonzales (L), Frank Sturgis (2nd L) and Bernard Barker (2nd R) were also CIA operatives who were also involved in the John F. Kennedy assassination

Boom: Nixon's Key Biscayne, Florida vacation home, shown in December 1971, was to be turned to rubble with a missile strike, according to Roger Stone's book 'Nixon's Secrets'

Their bumbling, which Stone claims as intentional, turned a professional surveillance operation of the Democratic National Committee headquarters into what history would regard as a 'third-rate burglary.'

'When they tried twice to get him killed, that doesn't work,' Stone told MailOnline.

'Then they infiltrate the Watergate break-in, and they sabotage it.'

Liebengood, the Watergate committee lawyer who first told Stone about the assassination plots, had been a longtime aide to Sen. Howard Baker, a moderate Republican who assembled his own dossier on CIA involvement in the Watergate affair.

Baker tried in vain for months to use that information to spark new committee investigations – which Democrats blocked at every turn.

'Baker’s incredible report was in the back of a 600-page book gathering dust at the Library of Congress, missed by the media and largely unknown until today,' Stone claims in his book.

When the senator later looked into the relationship between the president and his CIA director, Richard Helms, he summed it up by remarking that 'Nixon and Helms have so much on each other, neither of them can breathe.'

'Nixon also aggravated the CIA,' Stone told MailOnline, by demanding their records of of the JFK assassination, which he wanted as leverage over the agency.'

The president 'was furious when CIA Director Richard Helms refused to hand over the files,' Stone said.

The late former Sen. Howard Baker (L), who died two months ago, amassed evidence that the CIA infiltrated the gang of Nixon-era Watergate burglars and purposely set them up to be caught, all in order to being down the president

'Nixon's Secrets' is hefty at 661 pages, but readable and – mercifully – it requires little advance knowledge of the 1960s and 1970s, or the Watergate saga, to comprehend.

The book includes a longish but entertaining introduction to Nixon's political life. Stone, at one time the youngest staffer at Nixon's the infamous Committee to Re-Elect the President, is clearly fond of his subject but makes no attempt to whitewash his crime and cover-up that spiraled out of control and ended his presidency in 1974.

Killer? Frank Sturgis, one of the Watergate burglars, was one of two CIA assassins recruited to kill Nixon, according to Stone's book

And he explains clearly why the CIA would want Nixon out of the way and his later-disgraced vice president, Spiro Agnew, at the helm.

The CIA and the U.S. military Joint Chiefs of Staff were 'at war' with Nixon in 1969 and 1970, Stone claims, because 'they were opposed to the withdrawal of troops from Vietnam, they were opposed to the SALT [arms limitations] agreement with the Soviets, and they were opposed to the opening to China.'

Recalling the mood when Nixon entered the White House in January 1969, Stone told MailOnline that President Lyndon Johnson had frustrated his spies and generals by 'trying to conduct the war personally, picking bombing targets and so on.'

The CIA and the Pentagon, he said, 'felt handcuffed.'

'So now we've got a real hard-liner in Nixon. He's going to let us really go after the North Vietnamese,' Stone imagined them thinking. 'But of course that's not what happens. Nixon wants to get out of there, and they're violently opposed to that.'

'Their motivation is to upset this detente.'

In 1969, he writes in his book, top military brass were even running a spy ring inside the White House because they were 'desperate to know what Nixon and [his national security chief Henry] Kissinger were up to.

'In December 1971, Charles E. Radford, a twenty-seven-year-old navy stenographer assigned to the National Security Council, working closely with both Kissinger

and [his deputy Al] Haig, confessed to sifting through burn bags of top-secret White House documents and delivering these documents to the chairman of the Joint Chiefs, Admiral Thomas H. Moorer,' Stone writes.