Little more than a year ago, Keir Starmer could be described as what Napoleon called a “lucky general”. But now, six months after a landslide election victory, “lucky” is an adjective unlikely to be found anywhere near a prime minister more usually described as having made missteps and unforced errors. And yet, perhaps, amid this tumult – a shifting geopolitical landscape, an authoritarian to the west of us conceding to the imperial ambitions of another to the east – Starmer’s luck holds. For the situation offers him an unparalleled strategic opening through which my government can find and define its…