Saddam Hussein had his Iraqi forces attack Kuwait because of disagreements with Kuwait concerning a debt of $14 billion owed by Iraq and discrepancies regarding diagonal drilling of oil on the Iraq-Kuwait border; essentially, Iraq felt that the Kuwaitis were drilling diagonally across the border, taking Iraq's oil. However, Hussein did not anticipate the international community and the United States striking back after the Kuwaiti invasion with a full-scale air and missile attack against Iraq in January of 1991.
Hussein's forces invade Kuwait, a border country, in August 1990 with a force of 100,000 Iraqi troops in trucks, helicopters and tanks. At the time, Iraq had the fourth-biggest military in the world. The forces reached Kuwait City within an hour of the invasion and began an attack against the royal residence, killing the emir's brother. The Iraqi forces tortured and killed Kuwaiti citizens and others, looted their properties and set fire to 700 oil wells in the Persian Gulf.
Operation Desert Storm lasted until February 28, 1991. Coalition forces from 34 separate nations battled Iraq. The operation was led by the United States. The aerial and naval assault against Iraq lasted for 5 weeks. A ground assault began on February 24, 1991, and it was this assault that drove the Iraqi military from Kuwait. A peace agreement was negotiated in February of 1991, effectively ending the Gulf War, but leaving Hussein in power, a move that won then-president George Bush harsh criticism.