Sir Paul Scoon: The Queen's Governor-General during the American invasion of Grenada

Paul Scoon was Governor-General of the former British Caribbean colony of Grenada in 1983 when the little group of seven islands, best known for their beaches and their nutmeg, mace and other spices, became the world's No 1 headline. Grenada had been independent, though still a Commonwealth realm, since 1974 and Scoon, a native though UK-educated Grenadian, had been Governor-General since 1978. His was a largely ceremonial role until the events of October 1983 which led to a US invasion ordered by President Ronald Reagan at Scoon's request.

On 14 October that year, a radical leftist faction within the Grenadian government, backed by the army, seized power in a coup. The Prime Minister Maurice Bishop was arrested and replaced by his coup-friendly deputy, Bernard Coard. A few days later, Bishop was freed by supporters but soon killed, along with other cabinet ministers, by the local armed forces as mayhem reigned.

Citing the islands' independent constitution, Scoon made it known to British and other diplomats that, as the Queen's representative, he had the authority to take emergency charge. He was placed under house arrest by the military but not before his diplomat friends had relayed a message to President Reagan. The former colonial power, Britain, was too far away to react, and would anyway scarcely see it as in its interests to intervene in an independent country, albeit a former colony but not a British overseas territory like the Falklands, which it had defended a year earlier.

Fearing that Grenada could become the third leg of a Marxist-Leninist tripod in the Caribbean and Central America, after Cuba and Nicaragua, Reagan was receptive. He had the added incentive that there were around 1,000 Americans living or working in Grenada, many of them medical students at the University of St George's. And the US Marines barracks in Beirut had been blown up two days earlier, killing nearly 300 US and French servicemen.

On 25 October 1983, under the codename Operation Urgent Fury, some 8,000 US troops landed by air and sea in Grenada in the biggest US military operation since Vietnam. For the sake of PR, around 300 troops from Caribbean islands came in too and were paraded before the cameras as liberators, in a similar fashion to the way the Americans let the Saudis "liberate" Kuwait a decade later. A US Navy SEAL team led by Wellington "Duke" Leonard freed Scoon, and the two men became friends for life.

The shooting was over in little more than a week, with fatalities including 19 Americans, 45 Grenadians and 25 Cubans who had supported the communist takeover. As acting head of government, Scoon appointed a council of advisors to name a temporary prime minister – he made it clear he should not be a candidate – and democratic elections were held the following year, since which time Grenada's most worrying assailants and invaders have been the annual hurricanes, notably Hurricane Ivan in 2004.

Reagan and his administration defended the controversial invasion, which lacked approval by the United Nations, saying that it was necessary in order to protect American citizens and provide humanitarian aid to Grenadians; they also pointed out that Scoon had requested intervention. Reagan's spin doctors had issued a letter, dated the day before the invasion, in which Scoon allegedly requested a US invasion. In his memoir Survival for Service (2003), Scoon said the letter was probably faked by Washington for Reagan's own purposes but that he had, indeed, verbally through diplomats, requested American intervention. He remained a huge fan and friend of Reagan, describing him as "one of the greatest American presidents."

The son of a butcher, Paul Scoon was born in 1935 in Gouyave, a fishing village on the west coast of Grenada. He was born on 4 July, a fact he enjoyed sharing with Reagan in later years. Wishing to fulfil the Caribbean dream of the time – this was before the days when Caribbean universities emulated those of the old colonial powers – Scoon got degrees from the Universities of Leeds and London. He was the first to admit that the transmission of Bob Marley's genius to the developing British psyche of the epoch made his life and studies somewhat easier (he went on to get a Master's degree at the University of Toronto but always said his experiences in Leeds and London, not all of them good, shaped him as a Grenadian). Having fallen in love with two Englishmen – Chaucer and Shakespeare – he taught the words of those geniuses to wide-eyed kids back on his islands. He rose from teacher to official in Grenada's Education Ministry and on to a job in the government as cabinet secretary.

It was in that position that he was seconded as Deputy Director of the Commonwealth Foundation in London. In his memoir he recalled a black Daimler rolling up in front of his house at 27 The Avenue, Kew, west London, in June 1978. With a couple of neighbours peering from behind their curtains, several Caribbean men approached and entered his house. The only white man in the car remained behind. He was from Scotland Yard Special Branch and his guests told him he would not be needed. It was then that one of the men, the Grenadian Prime Minister Eric Gairy, asked Scoon if he would accept being the Queens's representative in his homeland. Scoon did, not imagining that he would become a power broker in an international conflict.

A staunch Catholic, Scoon suffered from diabetes and had been in poor health for some time. He was granted a state funeral and his death was massively mourned by his fellow Grenadians.

Sir Paul Scoon, politician and diplomat; born Gouyave, Grenada 4 July 1935; Governor General of Grenada, 1978–92; OBE 1970, GCMG 1979, GCVO 1985; married 1970 Esmai McNeilly (died 2004; two stepsons, one stepdaughter); died St Paul's, Grenada 2 September 2013.