Hawker Siddeley aggressively marketed the Harrier for export. At one point the company was holding talks with Australia, Brazil, Switzerland, India and Japan. Of these only India became a customer, purchasing the Sea Harrier. At one point China came very close to becoming an operator of the first generation Harrier. Following an overture by the UK in the early 1970s, when relations with the West were warming, China became interested in the aircraft as it sought to modernise its armed forces; British Prime Minister James Callaghan noted significant hostility from the USSR over the sales bid. The deal was later cancelled by the UK as part of a diplomatic backlash after China invaded Vietnam in 1979.