https://thinkprogress.org/trump-putin-subtweet-nuclear-weapons-5d95c32a08e0#.m0zvdueco
"Trump’s tweet comes almost exactly a year after he stumbled through a question about nuclear weapons during a GOP presidential debate, revealing he had no idea what the “nuclear triad” was. Since then, Trump’s made a number of concerning remarks about nukes, including being dismissive about the potential of a nuclear arms race on the Korean peninsula to refusing to rule out using nukes in Europe."
