The bombing of Tokyo demonstrated the power of the B-29 bomber. The cost of creating this machine exceeds that of the Manhattan Project, which developed the first atomic bomb.
After the end of the Battle of Britain came the bombing of German cities. In the war in the Pacific, the US and Japan successfully bombed naval and land targets.
Tactics on both sides were developed in both attack and defence. Both the bomber and the defence against it, became more effective through improvements in bombing, navigation, radar development and more.