What impact did the crusades have on the eastern and western worlds?

According to experts for every person killed outright by a nuclear blast four more would die later from the

Even though both ww1 and ww2 were in many ways the same conflict with basically the same countries facing off against each other, the way each war started was significantly different. the question is how what were the differences on how they started

In what way did expansion and global trade during the 15th to 18th centuries affect the economies of european countries