President Barack Obama has pulled off a historic deal with Iran on curbing its nuclear program but he and other global leaders now have tough work ahead turning an interim accord into a comprehensive agreement.
In a sign of how difficult the coming talks will be, some differences emerged between U.S. Secretary of State John Kerry and his Iranian counterpart in their public presentation of a key part of the deal - whether or not Iran preserved the right to enrich uranium.
Obama also has to persuade its ally Israel, whose Prime Minister Benjamin Netanyahu denounced the deal as a "historic mistake," that the accord will reduce and not increase the threat from its arch foe Iran. And he has to sell the accord to skeptics in Congress, including some in his own Democratic Party, who have been pressing for more sanctions on Iran.
The breakthrough accord was reached in the middle of the night at talks in Geneva between Iran, the United States, China, Russia, France, Britain and Germany. It won the critical endorsement of Iranian clerical Supreme Leader Ayatollah Ali Khameini and marked a clear turn in a U.S. relationship with Iran that has been fraught since the 1979 Islamic Revolution, and vexed for years over the Iranian nuclear program.
But nobody doubted that tough work lies ahead in moving on from the initial deal that allows a six-month period of limits to Iran's nuclear program in exchange for up to $7 billion worth of sanctions relief, while leaving both the program and the sanctions in place.
"Now the really hard part begins and that is the effort to get the comprehensive agreement, which will require enormous steps in terms of verification, transparency and accountability," Kerry said as he began a meeting with British Foreign Minister William Hague in London.
The agreement, which halts Iran's most sensitive nuclear activity, its higher-grade enrichment of uranium, was tailored as a package of confidence-building steps towards reducing decades of tension and ultimately creating a more stable, secure Middle East.
Iranian Foreign Minister and chief negotiator Mohammad Javad Zarif flew home from Geneva to a welcoming crowd,