The US invasion of Iraq has had catastrophic consequences in the middle east, including for al-Qaida, ISIS, and Saddam Hussein.

It has been 20 years since the U.S. led an illegal invasion of Iraq to topple the regime of Saddam Hussein. The invasion unleashed a series of catastrophes for Iraq, the wider Middle East and the world. These catastrophic outcomes remain with us today, and it is worth reflecting on the most enduring ones and their effects.

20 years after the US invasion of Iraq.

What do we mean when we talk about the Iraq War? In the flurry of appraisals marking the 20th anniversary of the U.S. invasion of Iraq, the question seems particularly relevant. Most of the bitter debates that preceded, accompanied and outlived the war now seem settled. But in many ways, that apparent resolution is illusory.

George Bush is seen in a picture during the Iraq War. 20 years have passed since the US invasion of Iraq.

The 20th anniversary of the U.S. invasion of Iraq is sparking much introspection. Some now see it as a grave error, others still think it was the right decision and others still who never supported the war now feel vindicated. With the benefit of 20 years of hindsight, three lessons from the invasion stand out.