He never really wanted world domination. His two goals were:

1. Unite Germans
2. Get rid of non-Germans in Germany. If there were a ton of Jews in France he would not care. He had a dream of a “Grossdeutschland,” a German state controlling Austria, and parts of modern day Poland, Denmark, Italy, Slovenia, France, and Belgium. He also wanted non-aryans exterminated. The world war started not out of his want for world domination, but because Poland refused to give him a portion of land with a lot of Germans in it, so he declared war on Poland, Britain and France declared war on him for declaring war on Poland, and that spiraled our of control.