Seven years ago this week, more than 3,000 people were killed in a horrific terrorist attack on America.
This prompted the US to launch its global "war on terror" by attacking Al-Qaeda strongholds in Afghanistan and invading Iraq.
Although the last chapter of the Iraq war has not been written, many observers think the Iraq war is the greatest strategic disaster in American military history even worse than Vietnam.
Critics say the post-Cold War military illusions and President Bush's personal ideology after 9/11 provided the foundation for the US' misguided strategies on the Iraq war.
Supporters, however, claim the war turned bad because of errors in judgement due to poor planning and co-ordination. They say what is more important is the final outcome.
How did 9/11 shape American military policies in the invasion of Iraq? And what lessons have the US learned from the Iraq war?
Our guests this week are Raanan Gissin, former adviser to the Israeli Prime Minister and Abdel Bari Atwan editor-in-chief of Al-Quds Alarabi.