An American official, asked about the consequences for the US and about the far-right links, said: "I do not see any upsides in the new grouping. I can only see downsides. In life it is normally best to do things when they have an upside."
Louis Susman, the US ambassador in London, in an interview with the Financial Times, issued what could be interpreted as a warning to the Conservatives not to try to disrupt Europe.
European diplomats said Clinton believed it would be unwise to try to overturn the Lisbon treaty in the unlikely event that it has not been ratified by the time the Tories come to power. She is also understood to believe that it would also be unwise for a Tory government to try to undo earlier EU treaties.
"Hillary Clinton is concerned that the Tories would not take a lead in Europe," one European diplomatic source said. "It is clear that this US administration does not believe that Britain's relations with Europe and the EU are a zero sum game – the wrong-headed idea that if you are close to one you can't be close to the other. The US wants Britain to be fully engaged in the EU – that makes Britain more relevant in US eyes."
The US are sending a signal to the Tories that Euroscepticism will endanger relations between Britain and America. But will it make any difference? The Tories are not pursuing their policies out of any sense of national interest, or conviction of any kind. They have decided to make a deal with the devil in order to get power.
William Hague under pressure from US over Conservative allies in Europe | Politics | The Guardian