David Cameron crosses his fingers and backs Europe
Given the genuine fury of Germany and France over the activities of the US National Security Agency, perhaps Cameron could do little else other than sign up to Friday's European memorandum expressing concern at the way the US has been spying on world leaders.
But the PM is almost certainly nudging and winking at the Americans, too, letting them know he's not taking any European fury too seriously. He can't. Britain is the key ally of the US when it comes to intelligence gathering – GCHQ and the NSA are closer to each other than they are to their own domestic agencies.
The NSA gives GCHQ tens of millions of pounds a year to fund programmes that Washington can take advantage of. It is highly likely any information gleaned from the NSA's snooping on Angela Merkelwould have been shared with GCHQ, and it's even possible the eavesdropping was conducted through Menwith Hill, the RAF base in North Yorkshire that is a British base only in name.
When the Intelligence Services Act was passed in 1994 it included a line – inserted at the last minute – that Britain's spy agencies could legitimately seek intelligence that would support the "economic wellbeing" of the country. This provision is one of the most opaque in the legislation and could be interpreted to justify espionage on just about any head of state or company chief executive, though this would require ministerial approval.
Would No 10Downing Street want to know Merkel's innermost thoughts? Of course it would. Knowing the mind of the world's most powerful woman would be invaluable during summits and bilateral talks, particularly at a time when Britain's membership of the EU is a source of constant tension.