Iran has stepped up its harassment of U.S. Navy ships in the Persian Gulf, angering the U.S. military and members of Congress. Since the international nuclear deal with Iran was implemented in early January, the number of incidents involving U.S. and Iranian ships in the Gulf has approximately doubled. Overall, there were more than 300 interactions between U.S. and Iranian forces last year.
http://thehill.com/policy/defense/295256-us-military-iranian-behavior-getting-worse-in-persian-gulf
