What were the major causes of Britain’s relative economic decline in the postwar period?

First, Britain suffered great economic losses in two World Wars and had gone heavily into debt to finance the war. Second, the era of the British Empire was over. India and other British colonies, which provided raw material & large market for British goods, gained independence. Third, Britain was forced to maintain an expensive military presence in many overseas locations until the end of 1960s. Fourth, Britain had to make Substantial financial contributions to NATO and the UN Security Council. Finally, Britain failed to invest in industry after WWII whereas its competitors like Germany and Japan caught up with Britain by investing in the most modern equipment and means of production.