The 43rd President George W Bush made the "Freudian slip of the century" during a speech at his presidential centre in Dallas last night.
It came as he referred to the "wholly unjustified and brutal" invasion of Iraq, when he intended to be talking about Putin's invasion of Ukraine.
Discussing the military assault, he said: "The result is an absence of checks and balances in Russia, and the decision of one man to launch a wholly unjustified and brutal invasion of Iraq."
Bush delivers his speech on Wednesday.
@Lowkey0nline
He then shook his head and amended his faux pas: "I mean, of Ukraine."
Seeking to puncture the awkwardness with humour, he said: "I'm 75!"
Staunch critics of the US invasion of Iraq, executed under the orders of Mr Bush, dubbed the attack unjustified and brutal at the time.
The premise of the preemptive invasion was the understanding that Iraq's leader Saddam Hussein possessed weapons of mass destruction (WMDs), however no evidence of WMDs were ever found.
U.S. President George W. Bush speaks to U.S. troops from Al Faw Palace at Camp Victory in Baghdad.
Kevin Lamarque
4,825 coalition troops lost their lives in the conflict, which ran from 2003 to 2011. Tens of thousands of Iraqis were killed in the war.
The slip-up for the former President drew widespread derision online.
"GeorgeWBush didn't do a Freudian slip. He did a Freudian Confession," tweeted US actor John Fugelsang.
Another user wrote: "Holy smokes GeorgeW Bush with an all time Freudian slip."
Andrew Stroehlein from Human Rights Watch tweeted: "Freudian slip of the century…"
Another tweeted: "The only constants in life are death, taxes, and George W Bush being completely unable to finish a sentence without owning himself."
Mr Bush made the error at an event centred on engendering trust in elections and democracy.
Speaking about the Russian conflict in Ukraine, Mr Bush said Ukrainian leader Volodymyr Zelenskyy was a "cool little guy" and "the Churchill of the 21st century".