I am afraid that, while public, we are not most of the time fully aware of how the secret services can operate as political agents or even as fake terrorists. This is specially true for what we call "the West", where somehow is has been too easy to fall into the hypnotic illusion of "everything is alright, we live in democracy", which is to some extent at least just propaganda.
For that reason it is important to understand the secret army of NATO, which came to be known as Gladio (on its Italian branch). I can remember well how the investigation in Spain was blocked and silenced and could only proceed with great difficulty and limited scope in Italy and Belgium of all NATO. In Italy specially it was found how the "stay behind" secret army had been involved in terror attacks which were blamed to leftist organizations.
So I believe it is important to watch this most informative documentary, or more precisely a video-conference interview with Danielle Ganser, who knows the matter better than most. It is in excellent English language with subtitles in Spanish (except the brief intro which is in Spanish). Alternatively you can just listen to it, I guess.
It lasts 90 minutes but is split into three chapters that you can watch separately.
You can watch it at TeleUNED, the channel of the Spanish National University of Education at Distance.