Two years into his presidency, Mr Donald Trump has no clear legislative strategy, no policy agenda, no plan for remedying his persistent unpopularity and a path to re-election sufficiently bleak that he is trying to bait a political naif, Starbucks billionaire Howard Schultz, into running as a third-party spoiler. Also, he might be impeached.

Yet, at the same time, amid all the domestic chaos and incompetence and political malpractice, this administration continues to act in foreign policy - not tweet obnoxiously, not rage behind the scenes, but act - as if it's following a serious grand strategy, one sufficiently coherent and plausible and forward-looking that future presidents might reasonably imitate it.