Iranian negotiators agreed to curb some of Iran's nuclear activities in a six-month interim deal in Geneva at the weekend - in return for £4.3 billion in sanctions relief. The deal, with several world powers, followed secret talks between the US and Iran.
Iranian military forces launched a series of massive military drills across nine provinces codenamed Towards Jerusalem as negotiations were going on.
French Foreign Minister Laurent Fabius said "Iran is committed to giving up the prospect of nuclear weapons. It's perfecly clear." US Secretary of State John Kerry insisted the deal had made the world a safer place. British Foreign Secretary William Hague said he thought Iran was "very sincere."
But Israeli Prime Minister Benjamin Netanyahu said the deal was a "historic mistake."
"Today the world has become a much more dangerous place," he said. "For the first time, the world's leading powers have agreed to uranium enrichment in Iran while ignoring the UN Security Council decisions that they themselves led. Sanctions that required many years to put in place contain the best chance for a peaceful solution. These sanctions have been given up in exchange for cosmetic Iranian concessions that can be cancelled in weeks.
"We cannot and will not allow a regime that calls for the destruction of Israel to obtain the means to achieve this goal."
Israeli officials seemed incredulous that US President Obama could enter into such an arrangement. Intelligence Minister Yuval Steinitz said the current deal could actually bring Iran closer to the bomb . Middle Eastern Arab nations are also suspicious.
A step towards peace? Or a recipe for disaster?
Time will tell.