The Russkies were certainly successful as assassins. Remember the microscopic poison-filled dart inserted in the leg of one of their enemies in the UK?
Another favorite trick (used by many operatives) is a drug administered during sexual intercourse that causes a fatal heart attack and dissipates long before the body is autopsied. I often wonder if Nelson Rockefeller was done in this way. The shame of daddy/hubby screwing around with a stranger in a hotel room effectively keeps the family from making many inquiries. Brilliant. Evil.
Guess they actually think their deeds will never be discovered. But God does see it all.
Although the KGB probably ordered the hit, the actual doer was a Bulgarian. The Ruskies liked to subcontract out the wet stuff to the Bulgarians because it gave them a cutout if the doer got caught. Not that it fooled anyone.