Even the largest navy in the world couldn't defend an island against the luftwaffe. They had a relatively small standing army, which could never be described as excellently equipped, and less so after everything was left in Dunkirk, was also ineffective against the luftwaffe. The bulk of Britain's defence came from Hurricane and Spitfire fighter planes, and a dwindling number of pilots bolstered by volunteers from the commonwealth and Poland. Britain's most effective weapon was the ordinary men and women who worked round the clock to build and repair the fighter planes, often whilst being bombed, with unfailing resilience, surpassing even the Germans in terms of output. So with mainland Europe conquered, America still following an isolationist policy, and the Soviets hoping for the best; Britain was indeed alone in defying the Nazis.