How to end a letter: Lenin vs Stalin

Lenin of the acerbic pen certainly knew how to end a letter, but has he met his match with Stalin?

Here’s Lenin:

I cannot share your regret at not having met. After your tricks and your conniving attitude, I do not wish to have anything to do with you except in a purely official way, and only in writing.

And Stalin’s epistolary conclusion:

One must possess the effrontery of an ignoramus and the self-complacency of a narrow-minded equilibrist to turn things upside-down so discourteously as you do … I think the time has come to stop corresponding with you.

Perhaps it is worth pointing out that the letters were not written to one another.