World War I

1. The type of warfare characterized by soldiers digging trenches for protection
2. The policy adopted by the United States during the early years of World War I, avoiding involvement in the conflict
7. The economic system that contributed to the tensions leading to World War I
8. The term for the intense pride and loyalty toward one's nation
10. The event that directly triggered the start of World War
11. The treaty that officially ended World War I
14. The assassination of Archduke Franz Ferdinand took place in this city
15. The military strategy of wearing down the enemy through continuous attacks and attrition
16. The diplomatic and military alliance formed by Germany, Austria-Hungary, and the Ottoman Empire during World War I.
18. The peacekeeping organization established after World War I to prevent future conflicts.

1. The alliance system that included Germany, Austria-Hungary, and the Ottoman Empir
3. The policy of building up strong armed forces to prepare for war
4. The ship sunk by a German U-boat, leading to U.S. involvement in the war
5. The agreement that ended the Eastern Front between Russia and the Central Powers
6. The naval strategy used by Germany during World War I, involving the use of submarines to sink enemy ships without warning
9. The military strategy of quickly defeating France before turning to Russia
12. The practice of shaping public opinion
13. The alliance system that included France, Russia, and Britain
17. The American President who proposed the "Fourteen Points" as a basis for the post-war peace settlement