WHEN it comes to the independence debate, the questions of Scottish EU membership and the border between Scotland and England regularly top the list of concerns. With Brexit long since realised, the two issues are now interlinked. Were Scotland to become a state and join the EU, its borders and relations with the residual UK would be defined by its EU membership.

The general suggestion is that an independent Scotland would seek to remain part of a revised Common Travel Area with Ireland and the UK. In that case, the movement of people across this island would be able to continue as now. Trade, however, would be governed by the EU-UK relationship. If the current EU-UK deal still applied, the barriers to trade between Scotland and England would be similar to those between the UK and France or the UK and Ireland.

In that context, it is natural that proponents of independence may desire a means of keeping the benefits of EU membership while avoiding disruption to Scotland-UK trade. Their preference would be to have “the best of both worlds”, as it were, when it came to trade with the rest of the EU and the UK.

By extension, it is unsurprising, if revealing, that an argument has developed in recent times that the answer to this challenge would be for Scotland to seek to replicate the Northern Ireland protocol in some measure. The protocol, which is part of the EU-UK deal, enables Northern Ireland to be functionally within the EU Single Market for trade in goods, while still remaining in the post-Brexit UK. The operation of the protocol is currently the subject of disputes between the EU and the UK government, but the premise is clear.

Despite its apparent appeal, that argument is seriously flawed. The Northern Ireland protocol is no template for Scotland in the event of independence. Actual assessment of the premise demonstrates it to be both contradictory and infeasible. The fact that the idea could gain any traction at all reiterates the unenviably poor level of understanding of the EU in Scottish politics.

The claim that an independent Scotland should use the protocol as a model to address the border question should be tested in two respects: what it would mean in practice and how likely the EU would be to accept it.

If Scotland sought EU membership, the process of joining would take place after it had become a state. The root of the protocol argument is that, although Scotland would eventually be an EU member, it would want specific and preferential trading terms with the UK not available to the other EU members. With an arrangement analogous to the Northern Ireland protocol, Scotland would in effect have minimal border controls (or even none) for trade in goods with the UK, despite the UK not being in the EU.

However, reducing or eliminating trade border controls between Scotland and England would necessarily require them to take place somewhere else. Northern Ireland has generally borderless goods trade with Ireland, in exchange for trade controls between it and the rest of the UK. Similarly, if Scotland had barrier-free trade with England, trade between it and the rest of the EU would have to be subject to border controls. Given that people moving between Scotland and most of the EU would already face border checks, since the former would not be in the Schengen area, the Scottish state would be electing to be a remarkably insular EU member on the edge of Europe.

In practice, the protocol model would isolate Scotland from the rest of the EU and blunt the professed economic advantages of joining the bloc. Moreover, since it would forfeit full access to the EU economy in exchange for better trade relations with the UK, the logical question is: why would Scotland bother to join the EU (or even to become independent) in the first place?

Even more pointedly, the EU would have no obvious reason to facilitate such an arrangement for Scotland. The EU institutions and member states backed the Northern Ireland protocol, despite the possible risks to the Single Market, because of the unique history of the island of Ireland – and Dublin’s adroit advocacy of the solution. Scotland’s argument, rooted in trade convenience instead of post-conflict peace, would not attract much, if any, EU support.

In the collective EU perspective, the case for a “Scottish protocol” would be unconvincing. The non-EU party of the current protocol, with partial yet significant access to the Single Market, is Northern Ireland, a small economy. In a Scottish protocol, the non-EU party would be the UK, one of the largest national economies in the world. Even with trade controls between Scotland and the rest of the EU, the new protocol would give the UK preferential access to the Single Market via Scotland – which the EU would certainly not support.

In failing both tests, the Scottish protocol argument betrays the often inward nature of Scotland’s EU debate – focused on domestic politics, disconnected from the realities of the EU. Real independence and EU membership would demand choices that could not be evaded.

Anthony Salamone is managing director of European Merchants