Why was the invasion of Iraq controversial how did the war proceed?

The invasion of Iraq in 2003 was controversial primarily due to the claims that Saddam Hussein possessed weapons of mass destruction (WMDs), which were later proven to be unfounded. Critics argued that the war was based on misleading intelligence and lacked international support, leading to widespread protests. The military campaign initially resulted in a swift defeat of Iraqi forces, but the subsequent occupation faced significant resistance, leading to a prolonged insurgency, sectarian violence, and destabilization in the region. Ultimately, the aftermath of the invasion raised questions about the U.S. foreign policy and its impact on global security.