Absolutely Spin. For all the pantomime acting out on our screens, the ducks are absolutely being lined up. One thing no one is in any doubt of, is the EUs ability or lack or ability, (all 27 members?) or the EUs potential lack of desire, to agree anything.
Springbreeze, the Apple issue, which sees both Apple and Ireland on the same side versus the EU, is Irelands desire to negotiate their own arrangements. Arrangements that have turned them around from financial disaster. Dare I say it, its both legal and financial sovereignty.
On the whole Brexit thing, I totally disagree with you. What youre suggesting, (and is yet another of the europhiles fearmongering campaign, a baseless fallacy) quite simply wont happen.
Both Northern Ireland and Ireland want an 'invisible' border. Its the EU who again would be the objectors in your hypothetical argument. That is in itself a politically grim situation. The EU would have to be the enforcers of this, despite the will of mainland UK, the UK government, the desire of the NI peoples and the desire of the government and peoples of the Irish Republic.
It is also absolutely do-able, as seen in Cyprus, so to 'discriminate' simply because they wish to act punitively, would be in breach of their own legislation. Yes Turkey is part of the customs union but there must be some form of 'customs union' between the UK and EU and Ill explain why.
As with Cyprus, there are key travel routes in and out, and controls both of 'people' and 'goods' would be managed at the arrival points. It wasnt hard to set up in Cyprus and its not hard to set up in Ireland/NI. There is already this arrangement with the ROI and the UK with regards the common travel area (CTA). Ireland currently act as UK migration control on their incoming routes, which then allows a broader application of the CTA to more travellers.
Customs already exist for goods and travellers from outside of the EU, and use of the CHIEF system they already have in place will easily support any level of tariff that may be applied.
To simplify, there are 3 immediate levels of 'tax' that apply to all goods. VAT, excise, and potential tariffs (BTI, Binding Tariff Information) Whilst everyone is tutting over the tariff issue, we already have controls over these 3 areas. All these processes support trade irrespective of in or out of the EU. The reason being, that its not enough to say currently 'all UK exports to EU member states are non-vatable', because theyre not. There are a multitude of circumstances that means goods can be currently sold into an EU member states business, and VAT must be applied. The core structure of these controls are Region of Origin and Destination. We already apply these processes as Origin/Destination procedures. An invisible border in Ireland will make no difference whatsoever to these processes.
The same rules of Origin and Destination applies to goods that are produced within the Republic and then sold over an 'invisible' border for use in NI, and would be an issue for customs enforcement, just as it is now.
Coming back to tariffs therefore, the issue is 'how much, if any'. (Not the actual ability to control goods)
How does that cost impact Ireland? It could be significant. Take Fuel. Ireland imports over 90% of its fuel/gas from the UK. Any additional tariff applied to that would be hugely significant.
Why will a customs union exist? Quite simply VAT. Theoretically, the UK could do away with VAT post Brexit. Its an EU Legislated tax. However, neither the UK nor the EU can afford to lose it. VAT accounts for over £150 billion of our total tax revenue. Thats a figure we could never recoup from any other area. The EU receive around 12% of its VAT revenue from the UK (That includes calculating the correction rebate we receive). Would the EU prefer to lose their UK VAT stream? Never never never, as theres no reason whatsoever to do away with it. Its free money now and itll be free money then.
What we are all witnessing is indeed classic EU pantomime and posturing from an organisation who knows appearances are everything.