Create a triple-entry vocab journal like the one below for all of the listed terms. I would used learnersdictionary.com for most of them, and you can also find many of them in the red History book. If you can not find a definition for a multiple-word term, try looking up each word separately and combining the definitions. To find the images, do not just look up the word on Google Images. Use the definition to help you decide what you image should be.
-Imperialism
-Isolationism
-Expansionism
-Conquest
-Militarism
-Mobilize
-Entangling Alliances
-Trench warfare
-U-boats
-Stalemate
-Reparations
-Armistice