Question

Why did George H.W. Bush go to war with Iraq?

Answer 1

The overwhelming evidence and beliefs prevailing in most of the world was that Saddam had or was about to have nuclear weapons. He had already used poison gas against his country's Kurds. It wasn't that much of a stretch to assume he'd use nukes if he could.

There are conspiracy theories that give all kinds of evil motives for Bush's action. But I've stated what the reasoning was at the time.