What was one of the events that led to u.s. involvement in wwi? u.s. troops were captured after they were sent on a peace seeking mission. germany sunk the lusitania and other american ships. germany invaded waters too close to the united states. the united states sunk german u-boats, aggravating tensions between the two countries. why did germany sign an armistice in 1918? germany's allies collapsed and retreated. the armistice was a temporary halt to the war and germany needed to refresh troops. turkey was the only ally left and that wasn't enough to fight. germany wanted to allow the central powers time to regroup.

1) Germany sunk the Lusitania and other American ships.

Germans knew that the US was supporting the Allies through passenger ships which were loaded with ammunition and other wartime needs.

After a while, Germans decided to apply the "Unrestricted Submarine Warfare" which means to sink every ship they encountered.

Following to this decision, the US warned Germany to withdraw this policy. Germany resisted and this was the one of the biggest reasons why the US entered the war.

2) Germany's allies collapsed and retreated.

After the surrender of Ottoman Empire and Austria-Hungary, there was not much left for Germans.

After six months of negotiations at the Paris Peace Conference, on June 28, 1919 the Allied countries signed the Treaty of Versailles with Germany, and others throughout the following year with each of the defeated powers. More than nine million combatants and seven million civilians lost their lives (1% of the world's population), an extraordinary figure, given the technological and industrial sophistication of the belligerents. It was the fifth deadliest conflict in the history of Humanity.c The convulsion that provoked the war paved the way for great political changes, with revolutions of a character never seen in several of the nations involved.The League of Nations was founded , with the aim of preventing a conflict of such magnitude from repeating itself; However, two decades later, World War II broke out. Among its reasons can be noted: the rise of nationalism, a certain weakness of democratic states, the humiliation felt by Germany after its defeat, the great economic crisis and, above all, the rise of fascism.