Why was the world divided into two parts during world war 1 give long and good anwer if you know the answer​

Long before the war began, the countries in these groups had made arrangements to work together and help one another if there was a war. So when war did break out in 1914, parts of Europe was already divided into two sides. Each of the countries involved got their troops ready to fight.

Explanation:

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they were byzantines

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