I would highly doubt that they were “double agents.” That “rumor” seems to have been started by people immediately afterwards who somehow wanted to incriminate the US for their actions; I think it’s sort of in the 9/11 truther category.
They followed a predictable jihadist path, seen by both the Russians and the Saudis (whose intel comes from different sources), and there is no way the US intelligence or security services should have missed these signs. But the fact that they actually ignored warnings IN WRITING from foreign services is more than incredible.
The Russians warned the FBI, and evidently the Saudis warned the DHS and possibly somebody in the State Dept. too. Also, I think Hillary may still have been in charge at the time they warned State.
I don’t see how these people are going to be able to wriggle out of this one, although of course the problem really goes up to Bambi. But he always avoids being blamed for things, and I have no hope that he’ll get caught on this one, either.
Sadly, I find it more credible to believe that Zippy is an anti-American puppet than to believe that the Tsarnaevs were double agents. It rings more true that they were just garden variety jihadists.
US intel ignoring the signs is incredible to me, too. I’d like to know how many such warnings we get. 10 in a year? 100? 1000? If we were swamped with millions of warnings, there could be at least an excuse. Somehow I doubt that is the case.