Timing is everything. So why now? The expulsion of the Mossad's London Head of Station coincided with two things. Both tell us the UK is genuinely angry.
The Foreign Office stressed that throwing the diplomat out was nothing to do with the Jerusalem/West Bank settlements row. However, it knows Israel is under the spotlight and that at the moment all related matters are highlighted.
So while it is true to argue that the two things are separate, it is impossible to see one without the other.
They are two parts of a bigger picture and the Foreign Office well understood that when it chose the day to make news.
It could have waited until next week when Parliament will be in recess.
Without David Milband's dramatic televised statement and the subsequent response by Ambassador Prosor, the story would have had less impact.
The British wanted to make a point. The announcement came one hour before Mr Miliband was supposed to be Mr Proser's guest of honour at the Israeli Embassy. Unsurprisingly, he made his excuses.
Another point was made by changing the government's travel advice. This now reads: "We recommend that you only hand your passport over to third parties, including Israeli officials, when absolutely necessary."
Leave to one side that most intelligence services (including the UK's) probably use cloned documents, the UK is genuinely affronted at the brazen use of its citizens' passports. As Mr Miliband said, for a friendly country to do so "adds insult to injury".
The Israeli government was given a slap, but the UK stopped short of a punch.
It stressed that the expulsion was for the cloning, and did not directly accuse Israel of the murder of Mahmoud al-Mabhouh in Dubai.
It also chose to keep in reserve the expulsion of Ron Prosor, who is possibly Israel's most experienced diplomat.
When he appeared in front of the cameras outside the Israeli Embassy on Tuesday he signalled that the voices of reason had prevailed in the internal debate in Israel. The phone lines between London and Jerusalem ran red hot. Some in Jerusalem had been arguing for retaliation. Mr Prosor appeared to rule that out, saying "It is now our intention to strengthen the firm foundations of our relationship."
As for the Mossad station chief? Well, if they're as good as the UK says, he can always come back on a false passport.