The United States is removing its Patriot anti-air missiles, and other weapons systems from Saudi Arabia.
Donald Trump says it is part of an effort to scale back on a military presence that he says doesn't benefit the U.S.
American weapons and fighter jets were sent to the kindgom last year after Saudi-Aramco oil facilities were attacked.
They were also intended as a deterrent, as tensions rose between Tehran and Washington.
But the reduction in the U.S. military presence is believed by some to be based on assessments Iran no longer poses an immediate threat to U.S. strategic interests.
Joel Rubin, President of the Washington Strategy Group.
Mahjoob Zweiri, Director of Gulf Studies Center at Qatar University.
Mohammad Marandi, Head of the American Studies Department at Tehran University.