So the FBI monitored a teenager for nearly two years as a potential terror threat, then... supplied him with the assault rifle he was planning to use. They caught him before he hit the Mall of America, which is the only reason this isn't a mass casualty event they facilitated. This is entrapment dressed up as thwarting. The FBI identified a radicalized kid, stayed close, and at some point decided the move was to arm him. Every agency that does this claims they were preventing something worse, but the baseline question never gets answered: would he have had the capacity to carry out an actual attack without the FBI handing him weapons?