The Wall Street journal reports that the base will be built in a secret location in Qatar. The facility will be just one part of a system meant to defend U.S. facilities and also its Gulf area allies against Iranian rockets according to anonymous U.S. officials.
This site plus two other sites in Turkey and the Negev Desert form an arc. The three sites together can detect any missiles launched deep inside Iran from northern, southern or western Iran. The radar stations also link to interceptor batteries throughout the region and to U.S. ships that have high altitude interceptor rockets.
Qatar is home to the largest U.S. military base in the region, All Udeid Air Base. Together with another base a total of 8,000 U.S. troops are in Qatar. In response to an Al Jazeera reporter's question about the site, the Pentagon replied."We have a number of allies and partners in the region with whom we seek to build greater cooperation, and our goal is to address a wide range of US security interests there." U.S. officials claim the U.S. Central Command intends to deploy a THADD (Terminal High Altitude Area Defense) system within the next few months. For more see this article.