July 27, 2012:
The U.S. is installing an AN/TPY-2 X-Band ballistic missile detection radar at the Al Ubeid air base in the Persian Gulf state of Qatar. Costing over a billion (mainly American) dollars to build in the 1990s, this air base is shared by Qatari, American, and other NATO aircraft. The base also serves as a forward headquarters for U.S. CENTCOM (Central Command, which controls U.S. forces in Afghanistan and the Middle East).
Earlier, an X-band radar based in Israel allowed Iranian missiles to be spotted when they are 5-6 minutes away, enabling the Israeli Arrow anti-missile missile to hit the Iranian warhead farther away and with greater certainty than with the Israeli Green Pine radar. The AN/TPY-2 radar at Al Ubeid would provide maximum warning of incoming ballistic missiles from Iran. The warning time would be used by several anti-missile systems to select and hit incoming targets.
The United States also has SBX (Sea Based X Band radar). This is an AN/TPY-2 radar built on a floating platform that can be towed to wherever it is needed. The SBX would be brought in if the danger was thought to be temporary, but installing a land based AN/TPY-2 radar in Qatar indicates that the Iranian danger is thought to be long term. Besides, the SBX is currently watching North Korea.