During the reign of Stalin, the Soviet leader tried several times to assassinate Yugoslavian president Tito. Fed up, Tito eventually sent a letter to Stalin, which read in part:
> *"Stop sending assassins to Belgrade. We've already captured five of them, one of them with a bomb and another with a rifle [...] If you don't stop sending killers, I'll send one to Moscow, and I won't have to send a second."*
No further assassins were sent.
That is the language Russian leaders understand.