My new piece at DIPLOMAT looks at the practical diplomatic options open to Julian Assange as he peers out of the window of the Ecuador embassy in London and tries to see the sky:

Right at the heart of diplomacy is a simple idea: good manners.

To be precise, the idea of courtly good manners was identified centuries ago when diplomacy was all about personal dealings between kings and popes, tsars and dukes. The 1961 Vienna Convention codified these time-honoured principles, and court cases around the world keep refining the rules as they apply in real life. But as the Assange case shows, diplomacy rests not on rules but on basic ideas of etiquette.

Embassies (and offices of international organisations) are guests in other countries. They need to behave nicely.

If I invite you into my house that does not mean that you are free to roam through every room, drink all my beer, try on my underwear, bring in scores of friends, use the house to plot crimes, or stay indefinitely. When I invite you in, I don’t give you a long list of all the things you can’t do: that itself would be impolite. Instead, I rely on your common-sense discretion and courtesy.

Ah. Our oldest friend. Common sense!

Right at the start of Mr Assange’s stay in the Ecuador Embassy, the British government messed up its bilateral diplomacy with Ecuador. It dropped a broad hint in writing that if the matter were not resolved satisfactorily, it might feel free to use its powers under the 1987 Act to remove the Embassy’s diplomatic status and haul Mr Assange from the building. Ecuador not altogether unreasonably saw this as a crass threat to its diplomatic presence in London, and noisily played their national pride card. The negotiations became far more intractable.

A trivial but as it turns out very expensive blunder. Note that the failure here was all about poor British negotiation technique. By making this implicit/explicit threat, we foolishly allowed the Ecuadoreans to ‘re-anchor’ the whole issue in terms of their national pride. They might have wanted to do this anyway, but still, it was not wise to hand them the opportunity on a gift-wrapp’d plate.

This explains why many superficially ingenious ideas for getting Mr Assange safely out of the UK under Ecuador’s diplomatic protection don’t work.

Give him political asylum! Make him an Ecuador diplomat so he has diplomatic immunity! Make him a UN diplomat so he has immunity! Transport him in the Ecuador ambassador’s car to the airport and up a ramp into a waiting Ecuador jet: the car and plane are Ecuador state property and so have diplomatic immunity – the Brits can’t touch him!

All piffle. World diplomacy would grind to a stop if anyone with a grievance could get into an embassy and claim ‘asylum’. No state would accept an embassy from a country that becomes known for granting diplomatic privileges to fugitives or troublemakers to help them escape the local jurisdiction.

Embassies are places where legitimate inter-state business is done, not sanctuaries for any suspected criminal who gets through the door. Under diplomatic practice established down the ages the UK government decides who gets diplomatic privileges and immunities on its territory. It won’t accept that Mr Assange is an Ecuador or UN diplomat to help him escape the UK and EU legal system.

Wait. Why not make Assange an Ecuador diplomat. He’ll have immunity, right? Wrong.

If Ecuador tries to nominate Assange as an Ecuador diplomat and escort him to the border, the Ecuador Ambassador and everyone else involved will be committing the serious UK offence of conspiring to pervert the course of justice, and will be liable to be expelled on the spot. The UK police will sensibly intercept any car carrying Assange, yank him out and arrest him. If this action is contested in court, no UK court will find for Ecuador/Assange: the embassy will be in trivial breach of elementary diplomatic good manners.

But diplomatic bags definitely have immunity. Pop him in one of those and carry him to a waiting Ecuador aircraft?

Diplomatic bags in principle enjoy immunity, but they still must comply with a host state’s legal procedures. If the host state is not satisfied that the bags contain only items allowed under the Vienna Convention, things can get awkward. If a man-shaped diplomatic bag is seen emerging from the Ecuadorean Embassy and UK customs officials prod it with a pitchfork to confirm that it contains only diplomatic items, a squeak of ‘Streeewth!’  would give the British government all the legal options it needs to insist that the Ecuador Embassy politely undo it and prove that the contents are covered by the Convention.

So what does all this mean?

Thus, the Assange situation is relatively rare. There is no point other than making a symbolic gesture in an embassy playing games with its relations with its host state and granting a foreigner asylum. That person still must get from the embassy to the border past hawk-eyed local police forces. And that is next to impossible. The Ecuador leadership know all this. Hence, they try no such tricks.

And so the weary days and weeks and months and years pass. Mr Assange sits lugubriously in the Ecuador Embassy, pasty from lack of sunlight, poring through Wikipedia to find a legal or diplomatic loophole he can sneak through.

It doesn’t exist.