I'm not really shocked that Belgium got attacked, since they are nestled between France and Germany, which is a pretty bad place to be if you're trying not to get attacked by terrorists. It's horrible, but not particularly shocking to me. If I had to bet where Isis would try to attack next, I'd say they'd try something in Switzerland (specifically Geneva) because that would mess with everyone really badly. Plus the Red Cross, World Trade Organization, and UN refugee agency are all based in Geneva so it would be a pretty big deal.
I swear to god NSA I'm not a terrorist I'm just really morbid.