Media playback is unsupported on your device Media caption Nuland declined to comment on the substance of the conversation but said the leak displayed "pretty impressive tradecraft"

Swearing scornfully about your allies isn't great diplomacy - but it is the revelation of the depth of the US involvement in the Ukraine crisis that really catches the eye.

Behind the banging of batons and the chucking of petrol bombs lies a very old struggle: whether Ukraine faces east or west, whether it does trade deals with the European Union or Russian President Vladimir Putin's ersatz Russian reflection of the EU, the Eurasian Union.

Much is at stake, not just for Ukraine, but others in the region facing a similar dilemma.

It seems Assistant US Secretary of State Victoria Nuland, whose conversation with US Ambassador to Ukraine Geoffrey Pyatt was leaked on YouTube, felt the EU was being tardy and inefficient.

Pity poor EU foreign policy chief Catherine Ashton (the term "foreign minister" was rejected by real foreign ministers, and her official title is "high representative of the Union for foreign affairs and security policy") - who has to check her every move with Berlin, Paris, London and Warsaw not to mention the Baltic states and the Scandinavians, indeed any of the EU's 28 countries who might have a view on how to handle Russia.

The US state department does not, yet, have to consult the governor of Alabama on such matters, and so Ms Nuland could instead plot with the ambassador on who should and shouldn't be in a new Ukrainian cabinet.

After all the NSA revelations, and German Chancellor Angela Merkel's umbrage at them, saying a naughty word about the main players in the region is excruciatingly awkward.

But it's the larger conversation, which shows the US is manipulating Ukraine just as much as Russia, that is the real diplomatic disaster.