What Creates A World War?

I believe that for a World War to happen there needs to be a chain of events that happens where several countries feel the need to fight. For example, World War 1 happened because of the complex system of allies that Europe had at that time. So when two countries got in a conflict, the other countries felt that they needed to join in because they were allies of each other. This eventually led to two different groups of allianced countries fighting against each other. For a World War to happen today, something along those liens would need to happen again, where two major powers get in a fight and other countries come to their defense, eventually causing another instance of big groups fighting against each other.

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