. >> i remember when we came back from reyjavik, i was practically summoned to the british ambassador's residence by margaret thatcher who said to me, george, how could you sit there and allow the president to agree to eliminate nuclear weapons. i said but margaret he's the president. >> ifill: that's all ahead on tonight's newshour. >> major funding for the pbs newshour has been provided by >> this is the engine that connects abundant grain from the american heartland to aaron's best-selling whole wheat while keeping 60 billion pounds of carbon out of the atmosphere each year. bsnf the engine that connects us. >> chevron, this is the power of human energy. >> and by the alfred p. sloan foundation, supporting science, technology, and improved economic performance and financial literacy in the 21st century. and with the ongoing support of these institutions and foundations. and this program was made possible by the corporation for public broadcasting and by contributions to your pbs station from viewers like you. thank you. >> woodruff: the obama administration today issued a new and rev