The Crusades were initiated by the Catholic Church in order to gain control of Jerusalem again, as it has fallen into the hands of the Muslims. While the Catholic Church had its goals in conquering Jerusalem, including wealth and power, it didn't foresee that the organizing of the Crusades its going to actually backfire on it and make the biggest blow to it.
The Crusades themselves had mixed outcome, sometimes winning, sometimes losing. What had much greater effect was that the Crusaders managed to bring in Europe lot of things from Asia which turned out to change the course of the history.
Because the Crusaders were in constant contact with the Muslims, they brought in numerous technological advancement in Europe. Also, through them, some of the ancient literature from Greece and Rome came back to Europe.
This prompted a huge interest among the people, especially the ones higher in the hierarchy, as they saw the potential of the new technology, but also the potential for the future based on the ancient literature. The end result was technological boom in Europe, loss of power by the Catholic Church, the Age of Discoveries, or all put in one, the Renaissance.
True.............................
Russia got the bomb
Spying was ramped on both sides.
There was an arms race and it was open, which was the main reason for Eisenhower warning against the Military Industrial complex. The military was just becoming far too powerful.
The allied powers used land as their mail gorund to fight on while the germans used the sea as a sneek attack bc the allied powers didn't see it coming that is how the ussr was sank bc of a surpisre attack from the Germans .