On the September 11, 2001 at 8:46 am, a commercial jet plane flew into the North Tower of the World Trade Centre in New York. As the news was beamed across the world, people wondered whether the crash had been an accident or an act of terror. Some five minutes later, viewers watching the smoke billowing from the gash in the building were stunned to see a second jet plane dart into view and fly directly into the South Tower. Suddenly, it was clear that the United States was under attack.
Over the next few days, the world learned that 19 al Qaeda terrorists, armed with box cutters and knives dodged airport security, and hijacked four planes.
So what followed the attack?
The 9/11 catastrophe set in motion a sequence of reactions and unintended consequences that continue to reverberate today. Some of the effects are - an unending war on terror, a sharp uptick in Western antagonism toward Muslims, the decline of US power and the eventual rise of leaders like the current US President Donald Trump.
Weeks after 9/11, President George Bush invaded Afghanistan with the support of allies, and quickly toppled the Taliban government and crippled al Qaeda. In 2011, under President Barack Obama, US forces killed 9/11 mastermind Osama bin Laden.
The US invaded Iraq in 2003, even though its dictator Saddam Hussein was not linked to 9/11.
9/11 also changed the world's opinion on India's fight against Pakistan-based terror groups.
For years, terror attacks in India were regarded by the international community as localised affairs arising out of the long-held animosity between New Delhi and Islamabad and religious bigotry in the two countries. The 9/11 attacks shattered that myth.