'To be honest my understanding of the Middle East is a lot deeper today than it was when I was prime minister quite frankly'

In his remarks, Blair was firm in his calling for the British military to engage in another ground war in Iraq. (Photo: Stefan Rousseau/AP)

Former U.K. Prime Minister Tony Blair admitted underestimating "forces of destabilization" in the Middle East when Britain joined the U.S. in invading Iraq in 2003, the Guardian reports, but stopped short of actually apologizing for the U.K.'s role in the Iraq War in remarks at an event on Tuesday.

In fact, Blair followed up his admission of culpability with a new call for war—this time against the terrorist group ISIS, which he repeatedly referred to as "these people."

"Be in no doubt if you want to defeat these people you are going to have to wage a proper ground war against them," Blair said.

At the event held by the Centre for Religion and Geopolitics, a think tank he helped found, Blair said:

For sure we underestimated profoundly the forces that were at work in the region and would take advantage of change once you topple the regime. That is the lesson. The lesson is not complicated. The lesson is simple. It is that when you remove a dictatorship out come these forces of destabilisation whether it is al-Qaida on the Sunni side or Iran on the Shia side.

[...] To be honest my understanding of the Middle East is a lot deeper today than it was when I was prime minister quite frankly.