Except as provided in subsection (c), if the President determines that a person, on or after August 10, 2012, knowingly sells, leases, or provides a vessel or provides insurance or reinsurance or any other shipping service for the transportation to or from Iran of goods that could materially contribute to the activities of the Government of Iran with respect to the proliferation of weapons of mass destruction or support for acts of international terrorism, the President shall, pursuant to Executive Order No. 13382 (70 Fed. Reg. 38567; relating to blocking of property of weapons of mass destruction proliferators and their supporters) or Executive Order No. 13224 (66 Fed. Reg. 49079; relating to blocking property and prohibiting transactions with persons who commit, threaten to commit, or support terrorism), or otherwise pursuant to the International Emergency Economic Powers Act (50
et seq.), block and prohibit all transactions in all property and interests in property of the persons specified in subsection (b) if such property and interests in property are in the United States, come within the United States, or are or come within the possession or control of a United States person.