Final answer:
The invasion of Kuwait by Iraq in 1990 was triggered by Iraq's accusation that Kuwait was stealing oil from their reserves on Iraqi land.
Step-by-step explanation:
The event that led to Iraq's invasion of Kuwait in 1990 was Iraq accusing Kuwait of stealing oil from reserves on Iraqi land. Iraq claimed that Kuwait was slant-drilling into Iraqi oil fields and accused them of economic warfare. This accusation triggered the invasion and subsequent Gulf War.
Learn more about causes of Iraq's invasion of Kuwait