one event that led up to the revolutionary war is the Boston Tea party. :)
Germany... Germany sent a letter/telegraph to Mexico , which said that if Mexico allied to Germany , Germany would've recovered the territories that Mexico lost in a war with U.S ... U.S. intercepted this message which was the last event that "forced" U.S. into war...
Texas
The assassination of Archduke Ferdinand was a major event that led to WW1
The Bolshevik Revolution was the event that led to Russia's early exit from World War 1. It was a costly war for Russia.
collapse of the Soviet Union
The civil war.
There were several of them. Two instances include:The annexation of Texas as a state in 1846 led almost immediately to border conflicts that escalated into war.The occupation of the port of Veracruz in 1914 to prevent an arms shipment to reach Mexico (it did, by the way). Mexico was in the middle of it Mexican Revolution, so it couldn't respond accordingly, but this event led both countries to the brink of war and damaged relations for decades.
James K. Polk.
The event that prevented an outbreak of war between the US and Mexico in 1917 was the diplomatic resolution following the tensions stemming from the Mexican Revolution and border skirmishes, particularly the Pershing Expedition. The US had sent troops into Mexico to capture revolutionary leader Pancho Villa after his raid on Columbus, New Mexico, in 1916. However, the US was preoccupied with World War I, which led to a focus on diplomacy rather than military confrontation. Ultimately, the need for stability in Mexico and the US's involvement in the war helped avert direct conflict.
the XYZ affair
pearl harbour