27/08/2014 12:58 BST | Updated 27/10/2014 05:59 GMT

Independent Scotland Will Be Rudely Awakened From Its Euro Dreams

Let's assume Scotland votes 'Yes' on 18 September.

Firstly, well done Alex, Nicola and every other 'Yes-er'; you did it. Congratulations. Alistair; sorry pal, you fought a good fight. Don't get too down, there's probably a cabinet position for you in May, if you head south of the new border.

Now, what next?

Once the hangovers clear, there'll be a huge 'to-do' list. 'Get rid of those pesky Trident missiles' will likely trump more pressing matters like 'decide what currency to use' or 'find out how much oil we do actually have'. Oh, and someone will have to phone the EU to see what the deal is with that.

For years, questions were asked about Scotland's EU status if a Yes vote transpired. The European Commission repeatedly refused to answer the 'accession versus succession' issue, not wanting to deal in 'what if' situations or influence anyone's democratic decision. So succession was always a possibility because everything is technically a possible if there is no definite confirmation of its impossibility.

Confirmation or not, there were still warnings about the hurdles and potential EU-related costs accompanying Scotland's separation from the UK (see video below).

A string of high-ranking officials publicly declared how difficult a transition to EU membership would be. Cries of 'scaremongering' were inevitable but even the Yes campaign eventually seemed to shy away from the topic. The only place that succession was really entertained was on Twitter, with ill-informed cybernats spewing the 'they can't kick us out of something we are already in' argument, failing to understand that if you leave the UK, you leave the EU member state that you were a part of, so you leave the EU.

But let's go back to our dream scenario. It's Friday 19 September. Scotland voted 'Yes'. Alex Salmond makes the phonecall to Brussels. What happens next?

Needing to provide answers, EU policy wonks go straight to the treaties guiding the functioning of the EU. They'll start with the Enlargement Policy because whatever way Scotland joins, the 28 existing member states would become 29.

While EU enlargement isn't a new concept, the idea of succession is. There are no rules to cover it. It doesn't exist in the EU treaties. As the laws stand, the EU is accession-only.

In the last four decades, over 20 new Member States have acceded in a series of enlargements. Others are still trying. Finland joined less than three years after applying whereas Turkey first applied in 1987 but is still far from acceptance. Recent applications have stalled due to 'enlargement fatigue'. New applicants face more stringent requirements and greater scrutiny as some members worry about the EU going too big, too fast.

Accession starts with an application to the European Council, the body made up of government representatives from every member state. If agreed, 'candidate' status is granted, following the opinion of the European Commission. A series of meetings then take place between the Commission and the candidate. This 'screening' involves a detailed examination of the candidate's conformity with the EU acquis and the 'Copenhagen criteria': the rules defining a country's eligibility to join the Union. Iceland completed this process in seven months, while Croatia's screening lasted one year.

The completion of screening doesn't mean the candidate is on an open road to membership. The next hurdle is the negotiation process where candidates negotiate with every one of the existing member states (acting together as the European Council) on the 35 chapters of the EU acquis.

This process is arduous. EU members won't give way on anything that potentially undermines their own nations. The biggest obstacle isn't any requirement on currency, border controls or trade. It is achieving unanimity amongst the existing member states.

Unanimity is a big deal in the EU. Negotiations can only be opened if all member states unanimously vote to do so. Unanimity is required to close each chapter of the acquis, meaning that problems over a single issue - maybe currency - can block an application indefinitely. After the negotiations, the European Council must consult with the European Commission and receive consent from the European Parliament. All member states must then ratify the agreements, unanimously.

It's easy to get bogged down in what this all means, but the overriding point is that joining the EU isn't easy. Unanimity will be particularly troublesome for Scotland, as some member states may wish to quell their own separatist movements who would be buoyed by a Yes vote. They need to ensure that Scotland does not come out of the negotiations with a good deal.

So nobody is saying that an independent Scotland would never be accepted into the EU. The application and screening process shouldn't be a problem. But the idea that Salmond, Sturgeon or anyone else could waltz through the negotiations and come out with opt-outs, currency agreements and everything else they want, is a total non-starter.

Scotland may wake up to independence on Friday 19 September, but if anyone suggests that it will wake up as an existing or even a soon-to-be EU member state, it could be a very, very rude awakening.