Even with your best friends , your trust should be with a limit , because there is a lot of thoughts in his mind that you do not know .
That was what exactly happened with a great terrible leader ; STALIN.
Stalin was at 1st a friend to Hitler , supplied him with wheat and raw materials , both wanted to conquer the lands and divide them between the two leaders , starting with the captured Poland taken by Hitler troops.
But Stalin , despite his craftiness , did not expect that his plans with Hitler will backfire on him .
It was more than A SURPRISE to Stalin when found the allied Nazi troops attack his territories , to the degree that unless the russian nature was in one line with Stalin , he might lose his state and probably his life also.