15-years on, the legitimacy and legacy of the Iraq War is still hotly debated. A U.S.-led coalition invaded Iraq on March 20th, 2003. The goal was to find weapons of mass destruction, but it turned out they didn’t exist. It was supposed to be a short war, but instead it led to a long occupation and gave rise to other problems.

CGTN’s Jack Barton Reports from Baghdad.

“Saddam Hussein and his sons must leave Iraq within 48 hours,” declared then U.S. President George W. Bush on March 17, 2003. “Their refusal to do so will result in military conflict commenced at a time of our choosing.”

Saddam refused to leave.

First came the so-called ‘shock and awe’ airstrikes. Then the U.S. military pushed into Iraq, backed by Poland, Australia and Britain.

“Tonight British service men and women are engaged from air land and sea, their mission: to remove Saddam Hussein from power and disarm Iraq of its weapons of mass destruction,” said Tony Blair, former British Prime Minister.

After an intense manhunt, Saddam was captured, put on trial and executed. But there was a problem. There were no weapons of mass destruction.

However, many Iraqis did initially welcome the U.S. troops.

“The wish for change was a dream for Iraqis, therefore toppling the former Iraqi government was not a mistake,” said Ahmed al-Sharify, a strategic studies expert. “What happened after the government fell was that we failed to provide a good example with our politics.”

Shiite Muslims, who had been marginalized under Saddam, found new freedom.

Sunnis who had been favored by Saddam suddenly found themselves out of work and often persecuted. The disbanded largely Sunni army morphed into an insurgency, while Shiite leaders founded militias.

They targeted each other, the coalition forces, but mostly civilians. Hundreds of thousands died.

The U.S. military also became embroiled in a series of controversies including the treatment of detainees at Abu Ghraib prison.

Out of the chaos grew extremist groups like al Qaeda in Iraq and ultimately ISIL, which easily overran predominantly Sunni areas, where people had felt persecuted since the fall of Saddam.

Today, ISIL has been defeated and the guns are now largely silent. The final verdict might be that the fall of Saddam Hussein and the occupation of Iraq brought some good, but also an unimaginable degree of suffering to a nation that is only just beginning to recover from a decade and a half of bloodshed.