Ironically, my first trip overseas when I was a kid was to Belgium. It was 4 November 1979, and the day we arrived was the day the US embassy was taken over in Iran. My dad had business at the embassy in Brussels when we got there, and everyone was on heightened alert. Just as you feel now, nobody then knew if other incidents would occur...even in Brussels (home of NATO, etc).
In the end, of course, nothing happened. I can understand why everyone is on edge. These things happen - and have always happened. Increasingly, calmer attitudes prevail.
I will say, as a US citizen, that I do have a bit of a target on my forehead for those who want to make a point about US policies. Maybe you can feel a bit of comfort in knowing that anti Belgian slogans and rallies are sorta rare.
Great chocolate though.
