Very disturbing, yet very real possibility

Yesterday on the pages of the Foreign Policy magazine was published an article whose author presents a very disturbing and frightening possibility, that Putin not only has a "nuclear option" but the he may actually use it. According to the author this may be an opportunity to destroy the credibility of both US and NATO. He may use it against to large European cities for which nobody in the West may want to die for: Warsaw and Vilnius.