It isn’t every day that Vladimir Putin threatens to hurl a rocket in your general direction, but neither is it out of the ordinary for the unflappable Boris Johnson to take such a taunt in measured stride. In a documentary named “Putin v. the West” that will air on the BBC today, the former leader and Conservative party stalwart said that in the course of a phone conversation with Mr. Putin before Russia invaded Ukraine, the Russian president told him, “Boris, I don’t want to hurt you, but with a missile it would only take a minute.”