The Washington Post reports, Putin has issued an ominous warning: “Russia this week sent a formal diplomatic note to the United States warning that U.S. and NATO shipments of the ‘most sensitive’ weapons systems to Ukraine were ‘adding fuel’ to the conflict there and could bring ‘unpredictable consequences.’”

If Putin gets desperate, he may well decide that his best move is to drag everyone into world war. If the Russian economy is going to tank, why not tank the world economy? If Russians are dying, why not have Americans die, too? Biden doesn’t want war. But if Putin does something crazy—uses a nuke, or makes an incursion into a NATO country—what is Biden to do? If this doesn’t keep you up at night, you’re not paying enough attention, or you don’t care.