1) Dollar Diplomacy: the use of a country's financial power to extend its international influence.
2) Big stick Diplomacy: Big Stick diplomacy is the policy of carefully mediated negotiation ("speaking softly") supported by the unspoken threat of a powerful military ("big stick"). ... President Roosevelt used Big Stick diplomacy in many foreign policy situations.
3) Spanish American war: U.S. victory in the war produced a peace treaty that compelled the Spanish to relinquish claims on Cuba, and to cede sovereignty over Guam, Puerto Rico, and the Philippines to the United States.
4) yellow journalism: journalism that is based upon sensationalism and crude exaggeration.
5) Allies/ World War One: France, Britain, Russia, Italy, Japan, and the United States.
6) Germany, Austria-Hungary, the Ottoman Empire, Bulgaria
7) Militarism: The belief or desire of a government or people that a country should maintain a strong military capability and be prepared to use it aggressively to defend or promote national interests.
8) Nationalism: Identification with one's own nation and support for its interests, especially to the exclusion or detriment of the interests of other nations.
9) Platt Amendment: The Platt Amendment is an amendment between USA and Spain, stating that United States would end its military occupation of Cuba. ... -The United States also reserved the right to intervene in Cuban affairs in order to defend Cuban independence.
10) Franz Ferdinand: Franz Ferdinand. archduke of Austria and heir apparent to Francis Joseph I; his assassination at Sarajevo triggered the outbreak of World War I (1863-1914)
11) Chemical Warfare (ww1): chlorine, phosgene, and mustard gas.
12) Air war ( ww1): Indeed, aircraft and balloons were used by the Allies from 1915 to 1918 to drop propaganda leaflets over occupied France, Belgium and Italy in order to combat German psychological warfare.
13) submarines (ww1): Type VII submarine/ German Type U 151 submarine/ German Type U 139 submarine/ Type XVII submarine/ Type IX submarine/ U-27-class submarine.
14) Battle of Jutland: The Battle of Jutland is considered to be the only major naval battle of World War One. It saw the British Navy losing more men and ships but remained a powerful tool while it left the German Navy too diminished to put to sea again while the war lasted
15) Battle of Verdun: The Battle of Verdun was fought from 21 February to 18 December 1916 on the Western Front in France. The battle was the longest of the First World War and took place on the hills north of Verdun-sur-Meuse
16) Battle of the Somme: was a battle of the First World War fought by the armies of the British Empire and French Third Republic against the German Empire. It took place between 1 July and 18 November 1916 on both sides of the upper reaches of the Somme, a river in France.
17) Battle of Meuse-Argonne: The Meuse–Argonne offensive was a major part of the final Allied offensive of World War I that stretched along the entire Western Front. It was fought from September 26, 1918, until the Armistice of November 11, 1918, a total of 47 days.
18) Zimmerman Telegram: The Zimmermann Telegram (or Zimmermann Note or Zimmerman Cable) was a secret diplomatic communication issued from the German Foreign Office in January 1917 that proposed a military alliance between Germany and Mexico if the United States entered World War I against Germany
19) Trench Warfare: Trench warfare is a type of land warfare using occupied fighting lines largely comprising military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artillery.
20) Treaty of Versailles: The Treaty of Versailles was the most important of the peace treaties that brought World War I to an end. The Treaty ended the state of war between Germany and the Allied Powers.
21) The Fourteen Points was a statement of principles for peace that was to be used for peace negotiations in order to end World War I. The principles were outlined in a January 8, 1918 speech on war aims and peace terms to the United States Congress by President Woodrow Wilson
22) League of Nations: The League of Nations was an international organization, headquartered in Geneva, Switzerland, created after the First World War to provide a forum for resolving international disputes.