1) Iraq invaded Kuwait in 1990 due to disputes over oil production quotas set by OPEC, war debt from the Iran-Iraq war, and territorial claims.
2) The US led a coalition of forces to defend Saudi Arabia and force Iraq's withdrawal from Kuwait. This resulted in military action known as Operation Desert Storm.
3) The invasion and subsequent conflict had severe humanitarian and environmental impacts across Iraq and Kuwait and displaced millions of people across the region. It also damaged Iraq's military and international standing.