Why did Japan target the US in World War 2?

The greatest known act of war down to the Ubited States down by Japan would have to be Pearl Harbor. Think of it like this: imagine Japan is your average, happy-go-lucky 5 year old child. Imagine the US as a medium-sized fire-ant hill. Now how does this scenario usually play out? The kid knocks over the anthill and starts jumping up and down on top of it. And about two minutes later, he starts wailing because he's getting attacked by a swarm of deadly insects. The next day, the kid knows not to go within 10 feet of the anthill, which is now larger, stronger, and meaner. Obviously, the time isn't to scale, but I hope you get the idea.