Separation of powers is the idea that power in a government should be broken up or divided. This is shown in the US government with the 3 branches of government. The Legislative, Executive, and Judicial branches work together yet separately to run the government. This makes sure that no one person or group can control the government, and all branches have to agree. This ties into checks and balances, where each government branch makes sure the others are doing their job and being responsible.
The sinking of the Lusitania caused the United States to enter the war. This was because it was a British ship and the United States is an ally of Britain.
