The Fukuda Doctrine is a policy named after a man named Takeo Fukuda, who was a Prime Minister of Japan a long time ago. The policy said that Japan would not try to become too powerful in the world or get involved in other countries' problems too much. This was because Japan wanted to focus on making life better for its own people instead of trying to control other countries. Basically, it was like saying "let's keep to ourselves and focus on our own problems instead of making problems for other people." And that's what the Fukuda Doctrine was all about!