In 1985, terrorists in Lebanon kidnapped four Soviet diplomats. The KGB identified the terrorists, kidnapped some of their loved ones, and then began returning them in pieces. No more Soviet diplomats were kidnapped.
More recently, some Somali pirates waylaid a Russian vessel but got captured in the process. The pirates now reside in Davey Jones’ Locker.
And the United States tracked Imad Mughniya, author of the truck bombing of the US Marines in Lebanon until he was killed. And US Seals blew away Somali pirates. Does that make us a country, like the former Soviet Union and Putin’s Russia, that reacts to every insult by assassinating someone? My bet is that nothing will happen in Qatar. The Russians would have much to lose (in the Caucasus for one)by a retaliation in a state where both the Muslim Brotherhood and the Wahhabi movements are powerful and dislike for Russia is tangible.