Will there be another world war? Most definitely, I say. Probably somewhere right as the oil supply is about to run out.
American Revolution: Colonists good, Tyrants bad. War of 1812: Americans good, British bad. WWII: Allies good, Axis bad. Korea: U.N good, Commies bad. Vietnam: U.N good, Commies bad. There is more than 1% of proof here.
Communists vs the free world. Religious wars. Wars in the Middle East over water sources. A second US Civil War that spreads. To name a few. No matter how unlikely, any of these could happen.
Yes there have been in the entire history of mankind, A LOT more....there are wars that you will NEVER hear about.....
This goes to show, I know more wars then you think. It was a war between the U.S Navy and the Barbary Pirates. They were kidnapping U.S sailors off our ships. So we sent 6-8 men a few miles away from the city of the pirates. They marched along with armed natives and attacked the city. They won outnumbered 5-1(estimated). It was considered the first Navy SEAL operation. It was in the 18th century.