The London nerve agent attack on former Russian spy Sergei Skripal and his daughter has been specifically ascribed to Russia by the United Kingdom prime minister, fully supported by the White House and American officials including at the United Nations. That attack itself – the first attack using weapons of mass destruction on NATO soil – calls for a significant response. But such a response is even more imperative when placed in the context of Russia’s ongoing hybrid warfare against the West and against vulnerable neighbors like Ukraine.In recent years, Russia and its surrogates have engaged in other instances of...