@William Bowles

I doubt Beria was a western agent. He WAS an intelligent sociopath with even worse behaviors than Allen Dulles, Beria likely knew it was about time for Stalin to lose control/die/retire- and that the only safe place for him then would be to take up Stalin's position. His moves to exclude the Red Army from Moscow and bring in all "his" security assets for the funeral pretty clearly telegraphed a coup attempt, which the rest of the top level + army command realized and managed to arrest & kill him before he could do the same to them (He had few friends and a LOT of enemies by the end).