Owing to his father's work, he grew up in Aberdeen and in various towns in England, including Brackley, Northamptonshire, where he attended Magdalen College School on a scholarship.
[2] Beasley had expressed a preference for the Royal Navy and thus reported to Devonport on 4 November 1940 to join HMS Impregnable for his initial training as a telegraphist; he was the only graduate amongst the men on the course.
Later that year the Tartar was at work in the Arctic and then in August escorted the battleship HMS Prince of Wales to Newfoundland for Winston Churchill's meeting with President Franklin D. Roosevelt.
In spring 1945, when he had finished the course and had undergone some further training in Vancouver and New York, he flew to Australia, where he was attached to the Allied Translator and Interpreter Section and was required to make his way to Manila, where he interrogated Japanese prisoners.
When the King George V entered Tokyo Bay for the surrender ceremony, which took place on the deck of USS Missouri on 2 September 1945, Beasley had to act as interpreter when a Japanese pilot came on board.
He was subsequently posted to the Naval Intelligence Section of the UK Liaison Mission in Tokyo, which represented British interests until diplomatic relations were restored in 1952.