By now, it really should not come as much of a surprise that yet another Russian has been attacked in Britain. Opponents of Russian President Vladimir Putin have been showing up dead in and around London for more than a decade.

In some cases, the trail clearly leads back to Moscow, with the use of such gruesome chemical agents as polonium (Alexander Litvinenko in 2006) or, in the most recent incident, a nerve agent (Sergei Skripal and his daughter, who both survived the poisoning but remain in serious condition).