The remaining tower of New York's World Trade Center, Tower 2, dissolves in a cloud of dust and debris about a half hour after the first twin tower collapsed September 11, 2001. Osama bin Laden and his organisation al-Qaeda, were held responsible for the attacks, that preceeded the US led war in Afghanistan.
One unintended consequence of the 2001 attacks was that it "fundamentally changed" the US and
The Chilcot Report, which took 7 years to write, was launched by former British Prime Minister Gordon Brown in 2009 to look into the United Kingdom's involvement in the war in Iraq.
The report, which is estimated to have cost over £10 million of taxpayers' money and runs to 2.6 million words, was chaired by former senior civil servant Sir John Chilcot, hence the name.
One of the many things the inquiry touched upon is the role of 9/11 in setting the scene for Iraq.
The report concludes that after the 9/11 attacks, the West abandoned its previous policy of "containment" in favour of stamping out threatening regimes, either through diplomatic or military efforts.
The Chilcot Report says then UK foreign secretary Jack Straw told the inquiry "that the attacks led to a consensus across the world that a policy of tolerating failing or failed states was unacceptable. The perception of risk changed."
Tony Blair first floated the idea of regime change in Iraq just three months after September 11, 2001.
Speaking at the launch of his long-awaited inquiry into the Iraq War, Sir John Chilcot said Tony Blair "urged Bush not to take hasty action" in the wake of the Al Qaeda attacks. But by December 2001, the thinking had changed and Blair proposed a plan to pursue regime change.
The former Labour Prime Minister "suggested a strategy for regime change in Iraq that would build over time, including "if necessary" taking military action without losing international support."
This was because Blair was worried that the US would jump the gun and attack Iraq, "which he considered would undermine the success of the coalition which had been established for action against international terrorism."
Chilcot says Blair chose to "emphasise the threat which Iraq might pose, rather than a more balanced consideration of both Iraq's capabilities and intent."
Tony Blair "overestimated" his ability to influence the US
The conclusion is part of the damning verdict from Chilcot on Blair's assessment of Iraq in the run-up to the war.
The report concludes that Blair "overestimated" his ability to influence the US and his the decision to go to war was based on "flawed intelligence."
Chilcot says the UK's concerns about weapons of mass destruction falling into the hands of terrorists pre-dated the 9/11 attacks. But the sheer scale of the carnage wrecked by Al-Qaeda in New York threw these concerns into sharp relief - suddenly they were the number one concern.
2,996 people were killed and over 6,000 injured on September 11, 2001, when four passenger airlines were hijacked by Al-Qaeda terrorists. Two planes crashed into the two World Trade Centre towers in New York, one into the Pentagon, and the fourth was heading for Washington but crashed in Pennsylvania after passengers tried to overcome the hijackers.
The UK went to war with Iraq alongside the US in 2003. The US stated the intent was to remove "a regime that developed and used weapons of mass destruction, that harbored and supported terrorists, committed outrageous human rights abuses, and defied the just demands of the United Nations and the world."
War with Iraq was part of the US' "War on Terror", following the 9/11 attack, as set out in this 2003 State Department document. The US said it wanted to "shut down the Salman Pak training camp where members of Al-Qaeda had trained."
However, the UK public strongly opposed military action and the UN refused to sanction it. The protracted conflict that followed the declaration of war saw 179 British military personnel killed and thousands of Iraqis also lost their lives.