Democratic peace theory

Democratic Peace Theory is an idea that says that countries with a democracy (a system of government where people choose their leaders through voting) don't fight each other in wars. This means that two countries that both have democracies won't go to war with each other. Scientists and historians think this is because people in democracies care more about the well-being of their citizens, so they don't want to start a dangerous war. We can see this in real life. For example, in Europe, no two countries with a democracy have ever gone to war with each other.