Nuclear program of Iran
U.S. President Obama reportedly sent a letter dated 20 April 2010 to President Lula of Brazil, in which he outlined a proposal of fuel swap. While expressing skepticism that the Iranians would now be willing to accept such a deal, having provided "no credible explanation" for the previous deal's rejection, President Obama wrote "For us, Iran’s agreement to transfer 1,200 kg of Iran’s low enriched uranium (LEU) out of the country would build confidence and reduce regional tensions by substantially reducing Iran’s LEU stockpile." Turkish Prime Minister Recep Tayyip Erdogan received a similar letter. A senior U.S. official told the "Washington Post" that the letter was a response to Iran's desire to ship out its uranium piecemeal, rather than in a single batch, and that during "multiple conversations" U.S. officials made clear that Iran should also cease 20% enrichment; however, the official stated "there was no president-to-president letter laying out those broader concerns".
Shia theocracy
Under the post-revolution Iranian constitution of 1979, Iran is government first and foremost by the Supreme Leader of Iran, who is responsible for the delineation and supervision of "the general policies of the Islamic Republic of Iran". The Supreme Leader is "Commander-in-Chief" of the armed forces, controls the military intelligence and security operations; and has sole power to declare war. The heads of the judiciary, state radio and television networks, the commanders of the police and military forces and six of the twelve members of the Council of Guardians are appointed by the Supreme Leader. The Assembly of Experts elects and dismisses the Supreme Leader on the basis of qualifications and popular esteem.  The Assembly of Experts is responsible for supervising the Supreme Leader in the performance of legal duties.