Recently I've run across videos of cold war era communist intelligence service defectors Yuri Bezmenov (aka Tomas Schuman) and Ion Mihai Pacepa.

These people seem as though they would be important historical figures, with their claims well-analyzed and cross-referenced by academics. But I've been able to find really nothing that seems at all thorough or impartial on them.

I'm hoping that I'm just being bad at searching, a task made difficult by a large amount of chaff created by the fact that some of their claims are excellent fodder for the conspiracy-minded.

Does anyone know of attempts at dispassionate, well-referenced analysis of their claims, and those of other cold war era communist defectors?

If not, any idea why not? It just seems bizarre to me that they would be overlooked by serious historians.