I remember the Chernobyl disaster in the 1980s. I also recall the fall of the Berlin Wall. This event marked the disintegration of the former USSR and the emergence of new countries. In the 1990s, I recall the Gulf War in Iraq and once again the fear of a global-scale confrontation. But the historical event I remember most vividly is the attack on the Twin Towers in New York.

I was 25 years old at the time, living outside the city for work. I was standing in line at a bank when the news broadcasts began showing the images. The next hours were truly shocking. Live and in real time, the two towers—iconic symbols of power and wealth—collapsed within minutes. A metaphor for real life?

This event forever changed global security policies and triggered the longest war we know of, in Afghanistan.