The story, both on Ukraine and Iran, is that President Trump wants a “deal” – and both deals are available – yet he seems nonetheless to have boxed himself in. Trump presents his Administration as being something rougher, meaner, and far less sentimental. It aspires to emerge, apparently, as also something more centralized, coercive, and radical. In domestic policy, there may be some truth to this categorisation of the Trumpian ethos. In foreign policy, however, Trump tergiversates. The reason...