Twenty years after Iraq was invaded by a “coalition of the willing”, led by the United States under former President George W Bush, the devastation left behind by the long war that ensued is still apparent in parts of the country.

Hundreds of thousands of Iraqis died between 2003 and 2011 when coalition forces left the country, leaving behind an unstable situation and a country torn apart by sectarian strife.

Looking back, some of the statements made as the US – strongly supported by its close ally, the United Kingdom – tried to convince the world that Iraq held weapons of mass destruction, along with others made as the war progressed, seem ironic today.

On September 24, 2002, then-UK Prime Minister Tony Blair told the British House of Commons that claims of WMDs were true and that action in Iraq to remove Saddam Hussein was imperative, declaring: “Of course, there is no doubt that Iraq, the region and the whole world would be better off without Saddam.”

The US entered the conflict confidently, as shown in comments by Donald Rumsfeld, then-US secretary of defense to CBS Radio Connect, who said on November 14, 2002: “The Gulf War [Iraq’s invasion of Kuwait] in the 1990s lasted five days on the ground. I can’t tell you if the use of force in Iraq today would last five days or five weeks or five months. But it certainly isn’t going to last any longer than that.”

But the war dragged on as Iraqis fought the occupation and sectarian tensions were exacerbated by the conditions.

Nearly six years later, on December 1, 2008, Bush told ABC’s World News programme: “The biggest regret of all the presidency has to have been the intelligence failure in Iraq. A lot of people put their reputations on the line and said the weapons of mass destruction is a reason to remove Saddam Hussein.”

Here are some other notable quotes from the war on Iraq, some illustrate what happened while some underline the futility of the war.