It seems that Britain shouldn’t try for customs union with the US because, and yet it should remain inside the EU customs union because the same because. There’s a certain logical tension there, no?
What about a Britain-U.S. customs union? That would be hugely problematic, among other things because given the asymmetry in size Britain would effectively be giving Washington complete control over its policy.
Well, yes, OK. The US economy is $17 trillion or so, the British £1.8 trillion maybe. But:
By contrast, the EU sets common external tariffs, which means that once you’re in, you’re in: once goods are unloaded at Rotterdam they can be shipped on to France or Germany without further customs checks.
The EU economy is some €15.3 trillion, the UK £1.8 trillion again.
That asymmetry is sufficiently different that the UK would lose from that loss of political power over trade with the US and yet gains so much from that same loss to Brussels, eh?
Hmm, what a little logical conundrum there.