After 9/11, we had to look at the world differently. After 9/11, we had to recognize that when we saw a threat, we must take it seriously before it comes to hurt us. In the old days we'd see a threat, and we could deal with it if we felt like it or not. But 9/11 changed it all.
It often happens that we blurt out things that may in some kind of way be harmful to us, but we are silent about things that may make us look ridiculous; because in this case effect follows very quickly on cause.
After 9/11, we had to look at the world differently. After 9/11, we had to recognize that when we saw a threat, we must take it seriously before it comes to hurt us. In the old days we'd see a threat, and we could deal with it if we felt like it or not. But 9/11 changed it all.