Russia is not the greatest threat to America—polarization is. And Putin knows that he can’t beat the United States militarily, so he is trying to make us tear each other apart.

He is right. Ron Brownstein has observed that Trump is a wartime president: war of red America and blue America. Sanders, too, will be a wartime president: war of the proletariat and the bourgeoisie. As president, each man would worsen (or does worsen) the divides among Americans, leaving Putin the winner.

America needs a unifier who will tell us that we are not each other’s enemies. Putin is ultimately not really supporting either Trump or Sanders; as a former Putin adviser put it last month, “our candidate is chaos.” Let’s not give our enemy what he wants.