Trenches and Blitzkrieg are both good tactics. Trenches stopped enemy's while Blitzkrieg provided brutal force. During WW1 there were trenches and tanks. But the tanks didn't really help much. Many people died in those trenches just like many died during the Blitzkrieg. For months neither side did a move because of no man's land. One change that we saw during WW2 was the Blitzkrieg that was used only by the Germans at the time. Which was formed and practice by Hitler because he wanted to take over nations and in his plan also was to take over the whole world. They had bigger tanks, dive bombers, planes, and also a very big army. Other nations also had these kinds of things. What was different was that they had huge amounts of tanks and planes and dive bombers coming in all at once. Which gave them an advantage to weaker nations to take over. This was a turning point in history. It was a turning point in history because after the war the U.S. said that they would not practice this at all. But when the Vietnam depression the U.S. went back to rethinking if they should practice the Blitzkrieg. They did practice this. The way the U.S. army fights our wars now are based on the whole concept of the Blitzkrieg. It changed the way we fight wars by using better tanks and an air-force to control the skies and big huge armies.
You can learn that Tank Production was very high in the United States (1943) and Soviet Union (1944). Germany’s Tank production was increasing but in 1945 it dropped back down. So you can also see how other nations where making tanks more and more because of the War.