Technological advancements, such as the beginning of the space race and things of that sort.
Because the treaties were not true, after the signing of the treaty of verse there was the assertion of Nazism. The treaties were not really taken seriously as they should, they were just a way for some countries to come out of war and others to gain from it.
Well there's no simple answer to this; the French and English have had a long history of discord- they weee at war for a hundred years after all!
