Scotland's referendum - nothing and everything changes

In a speech after the outcome he said Scottish people "have kept our country of four nations together. it would have broken my heart to see our United Kingdom come to an end".

The EU, watching nervously from the side lines, also welcomed the result. The No outcome removed the immediate political and legal maelstrom of what to do with an EU state that has just had a bit removed; and what exactly to do with that independent bit.

But others are contemplating similar ideas. All eyes are now on Catalonia which has vowed to press ahead with an independence 'consultation' in November.

The immediate lesson seems to be that states need to listen to their independence-minded regions. Ignoring them, or dismissing them, only serves to fuel a sense of anger. Cameron's devolution promises came only when the prospect of a Scottish independence suddenly became very real.

In Spain, Madrid's tough stance has also given a sense of righteousness to those who want independence.

And while Brussels was in a state of panic about the UK's possible break-up - the irony is that the EU can inspire such movements. It is seen as providing a safe harbour.

If statelets break away they are not necessarily going out into the big wide world alone. They can become members of the EU. (Yes, the EU commission did all it could to make it sound unlikely, but Scotland would have eventually joined the bloc).

In Scotland's case, this would have left a smaller, traumatised UK. And with the EU reliant on its large member states for a sense of foreign policy and defence, this matters. Numerous statelets concentrating on their own internal well-being is not necessarily going to project power into the world.

And this is probably what inspired European Commission President Barroso's statement - which his spokesperson later refused to elaborate upon - that Scotland's No leaves the EU "united, open and stronger".

Meanwhile, the next big question is whether Cameron chooses to make the same 'Better Together' campaign for EU membership as he did for Scotland staying into the EU.

He has promised a referendum on EU membership in 2017 if his party gets re-elected next year. The devolution to-do list he has just given himself on the back of the Scotland referendum looks like a campaign platform for the general election.

It very much looks like the two questions - UK internal devolution and EU devolution to the UK - will become entwined. This would leave Cameron overseeing the two biggest domestic and European policy questions of a generation.

If the Scotland referendum has taught us anything for the EU question it is this: The UK needs to be clear about what it wants.

And the EU should not descend into histrionics about a country asking for some, clearly defined, powers to go back to or be fixed at the national level.