ONE PICTURE captured the mood at June’s NATO summit in The Hague. At the centre of the leaders’ post-summit group photo stood a grinning Mark Rutte, NATO’s secretary-general. He had reason to be beaming: allies had just agreed to a new target of spending 3.5% of GDP on defence, along with 1.5% on things like cyber-security and infrastructure. Contrast that with the unhappy-looking Spanish prime minister, Pedro Sánchez, standing awkwardly at the edge of the group. Spain had emerged as the lone holdout against the spending pledge.