I really wasn't sure where to put this. I didn't want to put it under Entertainment, and it doesn't go in the news section, either. In my opinion, it does related to politics and government, so here it is. I haven't watched it yet, but I plan to. Anyone can watch it for free online, at least those here in the U.S. If you're outside of there and are interested, give it a whirl and see if it works. If not, you might be able to find it on YouTube or another site, or if you contact PBS(Public Broadcasting Service, now called Public Media), they might make it available. I watch quite a few of their documentaries, and I've been pleasantly surprised with how evenhanded they are. Here's the link.
Yes, and if some people get what they want, we'll probably be seeing more of it here. I ended up watching the documentary yesterday. There's a lot of detailed information in it, and I was multi-tasking, so I might have to re-watch it at some point. I would recommend that everyone watch it, because it shows how asleep Europe was at the wheel, while these people moved about freely and plotted their attacks. I had probably read their backgrounds in various articles following the attacks, but the show does a good job of mapping out the connections among the various parties and how the existing (at least at that time, although hopefully they've been changed by now) laws were totally incompetent to deal with this type of criminal/situation.
Didn't watch it but just want to say you don't read about any major terrorist attack in Hungary. They were criticized for not letting in the Syrian refugees at the time. They do have or had problems with Romanians crossing the border but to work, not bomb.