Japan took control of the island from Germany and colonies in East Asia, proposing to Italy that if it changed sides they would give it a part of Austria Hungary

The Ottomans were torn between going to war or not because they were worn out by the first Balkan war. But they ended up entering because some politicians wanted to enter the war, and these same politicians bomb Russia with battleships.

After the first defeats, of the Ottomans, they blamed the Armenians who lived in Ottoman territory for all their defeats, which ends in a genocide, ending the lives of a million and a half people.

What led the Germans to use chemical weapons and attack civilian ships

The Prime Minister and the King had different ideals of to which part of the war join, the country splitted and rejoined, so the Prime Minister won and Greece joined the allies

With all the hunger and the poverty, lots of internal conflicts happened in Russia, ending with the death of the zar and his family and the retirement of the war.

The reason for the letter is because the United States was selling supplies to the Allies, which did not suit Germany because they were at a point of wear and tear, also the United States was making a lot of profit thanks to this. Germany decides to send a letter to Mexico to attack the United States, because it was becoming a threat to Germany. The United States finds out about the letter and decides to go to Europe.

Germany surrendered and gave way to sign the Treaty of Versailles, which was pointed out as being responsible for the misfortunes caused by the combat.