The US and Israel have been staunch allies for decades, but that doesn't mean that the two nations aren't keeping an eye on each other. Der Spiegel reports that Israeli intelligence agents wiretapped US Secretary of State John Kerry the last time he tried to broker a peace deal in the Middle East, in 2013. The German paper cites "reliable sources" who say that some of Secretary Kerry's negotiation efforts between Israel, Palestine, and Arab states were carried out using unencrypted telephone equipment. Apparently the calls were intercepted as they were transmitted by satellite. The Israeli government then used the information it obtained to try "to reach a diplomatic solution in the Middle East."
It seems everyone spies on everyone, whether or not they're allies. German–US relations were dented last year when leaked documents revealed that the NSA was monitoring Chancellor Angela Merkel's phone conversations for years. Perhaps more surprising than news that an ally was spying on the US is that Secretary Kerry would ever be allowed to speak of official business on an unencrypted line. Nevertheless, the revelations likely won't help already-tense relations between US negotiators and Israel during the ongoing conflict in the Middle East.