It's been said that, if 11th September 2001 was the day the world changed for America, then 20th March 2003 was the day America changed for the world.
Four leading voices of the BBC's coverage in the last five years, Jim Muir, Magdi Abdelhadi, Lyse Doucet and John Simpson give their varying assessments of how the Iraq invasion and subsequent insurgency developed.
They chart the missed opportunities and faulty assessments by the Coalition and the murderous exploitation of Iraq's post-war frailty by Saddam loyalists and foreign Islamists.
We also look at how the ripples begun in the Sunni triangle have since spread globally affecting the political and diplomatic balance worldwide.
In Programme Four, John Simpson examines the impact of the Iraq War on America's international reputation and role.
Has the occupation of Iraq in the last five years affected America's own sense of itself and its clear moral superiority?
In the final part of the series, John Simpson looks at the root causes of anti-American opinion and questions America's effectiveness as a global superpower.
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