Israel is a very close ally for the United States and this position enables Israel to share some of the most advanced U.S. technologies. Geopolitics of the Middle East region and very hostile neighbors (technically Israel has been at war with Syria for decades) dictates the country to pursue and sometimes pioneer missile defense strategies, especially in the defense against the short-range and medium-range ballistic missiles.
The main threat not only for Israel but also for the international community as a whole is proliferation of ballistic missiles, especially if accompanied with weapons of mass destruction. This is particularly true of Iran which is trying to play more important role in the region.
AN-TPY-2 X-band radar was currently deployed in Israel. Israel is also widely believed to have dozens of nuclear warheads and intermediate-range (Jericho 2) and short-range (Jericho 1) ballistic missiles. As for strategic defense they possess MIM-23 Improved HAWK surface-to-air missiles, MIM-104 Patriot missiles as well as Arrow/Arrow 2 ATBM theater ballistic missile defense system.