During the Second World War (1939–1945), India was controlled by the United Kingdom, with the British holding territories in India including over five hundred autonomous Princely States; British India officially declared war on Nazi Germany in September 1939. The British Raj, as part of the Allied Nations, sent over two and a half million soldiers to fight under British command against the Axis powers. The British government borrowed billions of pounds to help finance the war. India also provided the base for American operations in support of China in the China Burma India Theater.