In 1917, British Intelligence intercepted what became known as the Zimmermann Telegram. This was a communication from the German government to the Mexican government that attempted to convince Mexico to declare war on the U.S. to distract Americans from getting involved in World War I. Even though Mexican President Carranza ruled out any such action, the U.S. had evidence of a threat to its national security and declared war on Germany and its allies, but not on Mexico.
Answer:
There was only one Confederacy and it was made by 11 southern states. They formed the Confederate States of America and adopted the US Constitution with some changes. All of them supported slavery and wanted to keep it. They fired the opening shots of the Civil War. On April 12, 1861, the South Carolina militia opened fire on Fort Sumter, a fort with a Union garrison located in the Charleston harbor. That was the first battle of the Civil War. It wasn´t the North who shot first.
Explanation:
3 Hellenistic kingdoms led by Ptolemy, Seleucus, and Antigonus.
There were a lot of factors. To start, the United States started pushing for Democracy, while the soviet union was obviously communist
These two systems are polar opposites, and because of those differences, there was obviously conflict between the two even during WWII (although yes, they were technically allies)
Oh yeh, and both sides had nukes now after WWII. Which meant we started pointing them at each other. And seeing who would pull the trigger first (Mutually assured destruction: you shoot a nuke at me, I'll shoot all mine at you) believe it or not, MAD was pretty effective at keeping the peace during the cold war.
But in 1950-1953, just a few years after WWII ended, South Korea (backed by the US) and North Korea (backed by communist China, soviet union) went to war (North invaded the South). We sent "ambassaders" to the South so they wouldn't be taken over by communists, but everyone knew they were really just soldiers. This is the beginning of "containment"
We wanted to "contain" communism. It started with the Korea War, and was cited as reason to become involved in Vietnam 10 years later.
TO SUMMARIZE: We went from an alliance to the Cold War because of our differing views on how the government and the economy should operate (Capitalism, vs Communism)
Nations started opposing each other because they were forced to ally with the United States, who was trying to spread Democracy, or with the Soviets, who were spreading communism.
Nations mainly disagreed on how their economies and governments should be run, which ultimately determined who they sided with during the cold war.