Two decades on from the 9/11 attacks, Americans talk about their experience of that day. 

Lew Evans, 43, Washington DC. Now lives in Ras Al Khaimah and is chief executive and founder of Nexus Resilience Group: "On that day I was at Quantico doing Marine Corps basic officer training. I was freshly commissioned as a lieutenant. The Marine Corps is quite a vigilant organisation … and when the attacks happened you can imagine things got very real, very quickly. We all got pulled outside on the lawns and an officer came out to tell us: 'We’ve just had the biggest terrorist attack in the history of the United States and you are all going to war. You better get ready, because there is nothing academic about this.' It did get very real for us and we were all involved in some way with everything that happened after that. We were all young back then and obviously not as experienced as we are now. In the 20 years of conflict that followed in Afghanistan and elsewhere, I learnt that terrorism was a tactic – not a nation against which war could be declared. I learnt the source of terrorism was 'angry young men', and that any strategy to defeat it must involve solving those conditions on the ground that cause the anger – economic, social and so on. I learnt that we have a lot to learn about the complexities of the world since the end of the Cold War and that the world is more interconnected than ever before." 
All photos: Antonie Robertson / The National

September 11, 20 years on - in pictures