His term was also marked by particular lows.
Washington and London fell out badly over extradition cases. The previous government’s willingness to send Abdelbaset al-Megrahi, the Lockerbie bomber, back to Libya still rankles, as does Theresa May’s decision to block the extradition of the hacker Gary McKinnon.
Mr Susman declines to offer a view of the Home Secretary, but it is fair to say that were she to become Tory leader and prime minister, the relationship is likely to be somewhat less special. “I’ve learnt that, close allies as we are, we’re not going to agree on everything, which is probably healthy.
“The Megrahi situation was a disappointment. He was allowed to go back to Libya and was supposed to die in three weeks and took almost two years. The whole extradition issue is one that is very important to us and we hope that the Mackinnon case wasn’t symbolic of the future.”