Diplomatic expulsions are unusual. But they are even rarer between friends and allies, which is why the expulsion of an Israeli diplomat marks a nadir in recent relations between our two countries. Even when friendly nations fall out, they try to limit the damage by agreeing not to publicise diplomatic departures. Here, the Government clearly wanted not only to communicate its displeasure to Israel but to broadcast it loud and clear to the British public.

This is surely explained in part by the extraordinary revelation that gave rise to Britain's initial protest: the discovery by police in the United Arab Emirates that 12 members of a team believed responsible for the assassination of a Hamas leader used cloned British passports to enter the country. Israel insists there is no proof that its agents were behind the murder of Mahmoud al-Mabhouh last month – and this remains the position. That there are links between Israel and the false passports, however, is hard to deny, given that many – if not all – of the real people whose identities were used reside in Israel.

The scandal of a friendly country – a democracy, as David Miliband emphasised yesterday – being prepared to take advantage of Britain in this way is not to be underestimated. But neither is the interest of the Government, and specifically the Foreign Office, in making its fury more widely known. British citizens had woken up to find their reputations compromised; the security of our national identity documents was impugned. Above all, though, the British authorities were made to look powerless – even, indeed, complicit, something Mr Miliband took pains yesterday expressly to deny.

It is reasonable to ask whether the Government's response would have been so harsh or so public, had relations with the Israeli government not already been close to rock bottom – what with the Gaza war, the stalling of the international peace process under Benjamin Netanyahu, and the arrest warrant that recently deterred the former Israeli Foreign Minister, Tzipi Livni, from visiting Britain. The truth is that diplomatic expulsions tend to be not the cause, but a symptom, of malaise. From here, the hope must be, UK-Israel relations can only improve.