US radar in Israel is aimed at Iran.

THE United States has deployed a sophisticated long-range radar system in Israel capable of providing crucial early warning in case of a missile attack.
There is growing anxiety in Israel and the US that Iran, which makes no secret of its long-range ballistic missiles or its uranium enrichment program, could launch an offensive against Israel.
According to the US newspaper Defense News , published by The Army Times , the radar system was flown to Israel in parts over the past week and will be installed at a military base in the Negev desert in the south of the country.
An unnamed Israeli official told The New York Times that the radar would serve not only Israel, but the US, and would be operated by 120 US staff.
Ephraim Kam, the deputy director of Tel Aviv University's Institute for National Security Studies, called the radar system an "important addition" to Israel's defences and said he believed the US was sending a message that "they are against any attack by Israel on Iran's nuclear facilities at this time but cannot leave us without protection". More.