Final answer:
Saddam Hussein invaded Kuwait, triggering the Persian Gulf War.
Step-by-step explanation:
The smaller country that Saddam Hussein, the former ruler of Iraq, invaded that resulted in the Persian Gulf War was Kuwait. Hussein accused Kuwait of slant drilling oil wells along the Iraqi border and removing oil that was legally Iraq's. In response, Hussein invaded Kuwait in 1990, aiming to gain control of its oil resources and port facilities.