With a few notable exceptions (Massie), Russian authors are far better and don't waste space explaining Russia to foreigners.
On the offensive plans controversy, I would recommend, if nothing else, reading the original book that started it all (in its updated edition), Ледокол. The author is just relentless in showing that Stalin was planning the attack for July 1941, and not later. It's really impressive, actually. But only read it in Russian - I understand the English version has a terrible, terrible translation.
ἡ δὲ κἀκ τριῶν τρυπημάτων ἐργαζομένη ἐνεκάλει τῇ φύσει, δυσφορουμένη, ὅτι δὴ μὴ καὶ τοὺς τιτθοὺς αὐτῇ εὐρύτερον ἢ νῦν εἰσι τρυπώη, ὅπως καὶ ἄλλην ἐνταῦθα μίξιν ἐπιτεχνᾶσθαι δυνατὴ εἴη. – Procopius
Ummaka qinnassa nīk!
*MySmiley*