M.A.I.N + The Spark
Militarism means an increase in army strength. For example if you bought new weapons. People would need to buy new guns and ammunition to fight with. The more weapons you had the more you were feared
Alliances is when one country is attacked and you defend them. Russia, France, and England all formed an alliance. This helped give them security. It was like "oh Britain was attacked now France and Russia will come to their side and defend them."
Imperialism is when you create a vast empire and become wealthy. Russia and Germany wanted to create their own empire and get raw materials. It was kinda like they were wanting to come in and take over and they were saying I want the materials that come from here.
Nationalism is when you stay loyal to your people and your country. This was Spain during the rule of Napoleon. It is like the saying if your friends jumped off a bridge would you? Well, they would. They did anything their country told them to do.
The spark is the beginning or the start. The main start was the assassination of Archduke Fraz Ferdinand. Militarism sparked this because it gave them new inventions. Alliances started this because it gave them a safety blanket. They always had someone by their side. Imperialism began this because they all had goals. Nationalism started this because they did what ever they were told by there country or people. This is M.A.I.N.