Something to notice in the linked news story; "The bill also applies penalties against Iran's central bank in an effort to hamper Tehran's ability to fund its nuclear enrichment program. The Obama administration is looking to soften the impact of those penalties because of concerns that they could lead to a spike in global oil prices or cause economic hardship on U.S. allies that import petroleum from Iran." Iran is definitely being targetted by the USA economically as well as diplomatically. It is being squeezed the same as the Germans and Japanese were before WWII, the result of which was they had no choice but to retaliate the only way they knew how.
Obama signs defense bill despite 'serious reservations'