In politics, principle is play-dough for adversaries. Take nationality. Gibraltar is as British as the royal family, or a cup of Darjeeling. No it isn’t: it’s as Spanish as Catalonia, or the Alhambra, or flamenco.

Spain's long-running case for owning Gibraltar (from Arabic Jabal al-Tariq, or ‘Tariq’s mountain’) seems to rest on the joined-on theory: a territory X belongs to nation Y if X is joined to Y. But that would lead to disputes between France and Germany, say. Maybe it's peninsular joined-on-ness that matters. But few people nowadays think, though some used to, that Austria owns Italy. Maybe the theory needs a bigger bit clause: X owns Y if Y is joined onto X and X is bigger than Y. Scottish nationalists, and the Portuguese, are unlikely to buy that one. Or maybe X has to be a lot bigger than Y. How much bigger? Germany compared to Denmark? Or Russia to Finland? And if Gibraltar ought to be Spanish, shouldn’t Ceuta and Melilla be ceded to Morocco?

Britain ingested the Rock in 1713 after the War of the Spanish Succession sped it on its path to becoming Top Nation. Spain tried to get Gibraltar back by force of arms, notably during the American Revolution, when they laid siege in concert with France. The 2006 plebiscite on sovereignty recorded an impressive 99 per cent in favour of remaining British. Surely that clinches it? Well, there's what political theorists call the boundary problem: answers to sovereignty questions depend on whom you ask. Gibraltarians? Britons? Spaniards? Well, you ask the people in the disputed bit, don’t you? Except perhaps for resident aliens, but including expats etc. Does that mean that if Lesotho votes unanimously for union with the UK, or Northampton to become part of Brazil, international law should snap into line? What if, as with Northern Ireland, the demographic is the upshot of earlier colonisation?

Speaking at the weekend in Kent, from what one can only hope was a secure unit, Lord Howard, the former Tory leader, slavered over the prospects of launching another Falklands flotilla in what remains of the imperial bathtub. Tuesday's edition of the Sun went with 'Up yours Señors!' and quoted 'retired police officer James Parody' as saying: 'I'm glad the British bulldog has finally shown its teeth.' The patriotic bosom distends with pride.

It’s Brexit that has brought us to this, as we live out the contradiction between little Englander micro-nationalism and dreams of projecting global power. (The Sun for some reason doesn’t mention that 96 per cent of voters in Gibraltar last June wanted to stay in the EU.) The EU talks of giving Spain a veto over any free trade deal that includes Gibraltar, while Spain makes mischief by signalling that it won't block an independent Scotland's joining the EU, despite its worries about Catalonia. In one of the tastier ironies, UK expats in Spain, including the denizens of the 'Costa del Crime' who'd otherwise be Sun-worshipping Brexiters, are having their collars felt by the prospect of being forcibly returned in a future trade deal to the Blighty they dearly love but would never want to go back to.

One demographic so far unconsulted are the three hundred or so Barbary macaques on the Rock. Despite the legend that Gibraltar will remain British as long as the monkeys are there, they've been present longer than Britain has, and indeed Spain; they were brought in as pets by the Moors. Maybe they'd favour union with their cousins on the Barbary Coast. When the population dwindled to a handful during the Second World War, Churchill ordered an emergency infusion of reinforcements from forests in North Africa to shore up morale among Gibraltar's humans. Postwar, the monkeys have picked up aggressive raptor behaviour from contact with tourists, ripping open handbags in a futile search for oranges. How gratifying it is for us humans to have outgrown such barbarism.