Before Donald Trump was a politician he was a property tycoon. Naturally, he thought he could fix the Ukraine war with a real-estate deal. In exchange for a ceasefire, Vladimir Putin would get to keep territory he had already seized. But before Putin was a politician he was a KGB agent who mourned the collapse of the Soviet Union. His idea of a fair solution begins with Ukraine’s total submission to an imperial Russian motherland. There is no evidence that Trump was ever appalled by that ambition or by atrocities committed in pursuit of it. But he does now declare...