James Schlesinger: US government official who served Nixon and Ford and became the most unpopular director in the CIA's history

To measure the varied but turbulent career of James Schlesinger in the highest reaches of US government, consider these few facts. He was surely the most unpopular director of the CIA in its history – even though he held the job for just three months. As Defense Secretary he insulted President Richard Nixon to his face, and survived. In 1975 he was sacked from that post by Gerald Ford, Nixon's successor, for arrogance and insubordination. Two years later he was named America's first secretary of energy by Jimmy Carter, a Democrat, but was forced out of that job for basically the same reasons.

No one ever doubted Schlesinger's brains. It was the way he used them that jarred. Born into a wealthy Jewish family in New York City, he attended Harvard (where he was a classmate of Henry Kissinger) and graduated summa cum laude. He then spent a year in postwar Europe on a travelling fellowship before returning to Harvard to take an MA and then in 1956 a PhD, in economics.

A spell teaching at the University of Virginia followed, before he moved to the Rand Corporation, where he rose to become director of strategic studies. At Rand he caught the attention of Nixon's campaign and joined the new administration in 1969 as deputy budget director.

His ascent was swift. By 1971 he was chairman of the Atomic Energy Commission, the regulatory agency for the country's developing civil nuclear industry. Never one to suffer fools, Schlesinger was already displaying the abrasive managerial qualities at the AEC that were the hallmark of his career. He was also a proven Nixon loyalist, and in February 1973 the President named him CIA director to replace the sacked Richard Helms.

Helms had refused to do Nixon's bidding as the Watergate crisis began to deepen, and the paranoid President saw the agency as an enemy. Schlesinger's mandate was, in own words, "to cut it down to size" – and he did so with a vengeance. Not only did he sack seven per cent of its staff, turning the axe in particular on the old guard of the clandestine operations division. Schlesinger also ordered senior CIA officers to tell him about earlier illegal activities they knew or suspected.

It was a licence for savage bureaucratic score-settling – and, some say, may have hastened Nixon's end by encouraging disgruntled employees to leak details of his own efforts to bring the CIA into the Watergate cover-up. Mercifully for the CIA, the Schlesinger purge ended when Nixon moved him to the Pentagon in June 1973.

But the style had been established. A rising young CIA Soviet analyst named Robert Gates – later destined to follow in Schlesinger's footsteps as head of the Agency and Secretary of Defence – wrote in his memoirs of how the new director was "crude, demanding, arrogant and dismissive of experience." With his uncombed hair and shirt-tail hanging out, Gates noted drily, Schlesinger "was most definitely not 'old school.'"

At the Pentagon, Schlesinger was a better fit. His background at Rand and the AEC made him an expert on nuclear strategy. A classic conservative defence hawk, he argued that now the Soviet Union had achieved nuclear parity with the US, military spending had to rise. His rough ways made him one of the few Pentagon bosses to dominate the entrenched military bureaucracy. As one grudging admirer put it, a Schlesinger bad mood "could melt the stars off the shoulders of a four-star general."

In the end he established a good working relationship with the top brass. But Schlesinger did not confine his aggressiveness to the military. He clashed with Kissinger, now Secretary of State, over détente, and, as Nixon sank into the mire of Watergate, became ever more arrogant with the President himself. In June 1974, at a meeting of the national security council, the two disagreed over an arms control proposal, and Schlesinger made a sneering joke about Nixon's negotiating skills. The remark, Nixon noted in his diary, was "an insult to everybody's intelligence, and particularly to mine."

Schlesinger, however, was unabashed, and Nixon was far too weak to sack him. Fearful of the President's erratic mental state, he gave orders that any nuclear policy instructions by Nixon to the joint chiefs of staff must be vetted by him first. As Watergate reached its climax, the Defense Secretary even drew up plans for an airborne unit to be deployed to Washington in the event that Nixon refused to resign.

At first Gerald Ford, too, was cowed by Schlesinger. But his patience snapped, in part due to continued resistance by his Defense Secretary to détente, in part due to his inability to get on with the Democratic Congress. The last straw was when Ford learnt that Schlesinger had ignored orders to carry out strikes against Cambodia in May 1975 in retaliation for the seizure of the US-registered freighter Magayuez. For his insubordination, Schlesinger was finally sacked.

But he was not out of government for long. One of the few top national security officials to serve both Republican and Democratic Presidents, he was chosen by Jimmy Carter as his energy adviser, and in 1977 became the country's first Secretary of Energy, heading a sprawling new department into which the old AEC had been subsumed. But, predictably, the relationship did not last long. After two years, Carter dismissed him in large measure for the same reasons Ford did. Schlesinger was simply too rude, too impatient, and too contemptuous of those who dared disagree with him.

Retirement was not for Schlesinger. He served on many corporate boards, especially in the energy and banking sectors. His intellect and experience earned him positions on various governmental advisory boards on defence and security. To the fury of environmentalists, he also emerged as a prime sceptic about global warming.

RUPERT CORNWELL

James Rodney Schlesinger, economist and US government official: born New York 15 February 1929; Associate professor of economics, University of Virginia 1955-1963; Staff member, then director, Rand Corporation 1963-1969; Chairman Atomic Energy Commission 1971-1973; Director, Central Intelligence Agency 1973; Secretary of Defense 1973-1975; Secretary of Energy 1977-1979; married 1954 Rachel Mellinger (died 1995; four sons, four daughters); died Baltimore 27 March 2014.