The revelations in the Guardian and New York Times last Friday that the target list of a joint NSA-GCHQ surveillance operation included Israel’s former prime ministers Ehud Olmert and Ehud Barak elicited only a muted response in Jerusalem.

Strategic Affairs and Intelligence Minister Yuval Steinitz provided the only official response in an interview with Channel Two on Saturday night. He said: “The fact we were spied upon is unacceptable. We don’t spy on the president of the United States.” However, Mr Steinitz belittled the report and said that no secret information had been revealed.

There are several reasons for this low-key response.

First, although the main targets were Israel’s most senior figures — the prime minister and defence minister — the email accounts that had been hacked were not being used for classified communications. The second reason is that Israel has a close intelligence-sharing relationship with the US and no-one in Jerusalem is interested in rocking the boat.

Moreover, there is a general assumption that the Americans are constantly using every means at their disposal to find out about Israel’s plans, especially anything to do with the possibility it may launch an attack on Iran.

“At every meeting in which we make sure that safety precautions against electronic surveillance are being observed, the main worry is not the Arabs, but the Americans,” said a former senior security official. “The ones who have the best equipment and resources are always the Americans.”

But Israel shares most of the sensitive information it has with its American allies and, in recent years, Britain has also been a key strategic partner on intelligence matters . In fact, Israeli defence experts are skeptical that any covert listening could have yielded anything the US or the British did not know already.