At the beginning of the twentieth century, Europe was controlled by a series of alliances that served to check any one power from becoming too large. These alliances had worked for a number of decades, and there had been little in the way of warfare on the continent.

However, competition existed among the powers, especially in colonial development. In particular, Germany’s desire to have more colonies and a correspondingly larger navy put it in direct competition with the British Empire.

Zimmermann Telegram — a 1917 telegram sent by Germany’s foreign minister offering an alliance with Mexico in return for Mexico causing disturbances along its U.S. border. Sykes-Picot Agreement — a secret agreement reached between France and Britain in 1916 to partition areas of the Middle East after the war. War Industries Board (WIB) — a U.S. federal agency created in 1917 to control the economic and industrial output of factories in times of war. Women’s Land Army — a British program to help women ensure enough foodstuffs were produced on farms while men served in the military.