Okay I only know 2 things: The sinking of the Lusitania and Zimmerman Telegram. What started the war the ruler of the ottoman empire was assassinated and what expanded the war was the Zimmerman telegram.
They were militaristic, independent, *insert form of gov. they had here*, and a thriving army. (I believe there gov. was a democracy or an oligarchy but i could be wrong)
It means exploiting the resources of the conquered country for the benefit of the conqueror. Imperialism means creating an empire, expanding into the neighbouring regions and expanding its dominance far. Colonialism is termed as building and maintaining colonies in one territory by people from another territory.