We too are facing this issue. We traveled to Jamaica one week after 9/11, we were suppose to leave 2 days after, but I wasn't ready to travel at that point. I cried all the way to Jamicia I was so terrified, and I use to fly all the time for business. I again cried all the way home. It was a wonderful trip, but wasn't easy flying on that plane.
Last year I went on a 3 week trip, without my DH, with my girls, road trip to WDW, and at first it was very hard to be alone with them, in major cities and in major parks. There were heightened terror threats, some to the coast of FL, which is where we were staying. I called home every night crying to my DH about maybe we should come home. He forced me to keep going. That was one of the best things he ever did for me.
We are now planning on another trip to WDW, which could be a huge target, since it's so "American" and there are so many people there at once. I am nervous. I have had second thoughts. I worry because we'll be leaving our oldest home, she'll be in college. But we had first looked at a trip to the Crib., but then decided on WDW. I'm sure we'll go unless something major happens, because at least we'll be on American soil, which helps.
The most important thing tho, is if we cancelled they'd be winning and I won't let them win! I hope and pray that all will be well in our world, but I also know that anything can happen anywhere and at anytime and I want to live life to the fullest until it does.
Pammy