At last week’s nuclear security summit, President Obama “issued a specific warning” to the Iranian regime, the New York Times reported. The President is working to secure United Nations Security Council support for new multilateral sanctions and penalties against Iran unless it curtails its nuclear weapons program.

Even if other nations decline to join the President’s effort, the climate for Iranian trade could change markedly. Both houses of Congress have passed bills that will build on the existing Iran Sanctions Act (ISA), which was passed in 1996. State legislatures are also increasing pressure on businesses that trade with Iran. Oil and technology companies have already been affected by these moves, giving a glimpse of possible dislocations to come.