The usual voices have denounced last week’s nuclear framework deal with Iran. Israeli Prime Minister Benjamin Netanyahu warned that the way is now open for an Iranian bomb. Republican Senator Mark Kirk was yet more apocalyptic, warning that lifting sanctions against Iran "dooms the Middle East to yet another war," adding "which we all know is going to end with a mushroom cloud somewhere near Tehran." The Iranian Republican Guard is reportedly as distressed as Kirk’s Republican party.

However, the deal has been very well received by most well-informed people. Even voices who could have been expected to be opposed, like King Salman of Saudia Arabia, have given the deal qualified support.

This is because President Barack Obama and Secretary of State John Kerry have achieved what many observers thought was impossible. They have constructed a deal which makes it virtually impossible for Iran to build a nuclear bomb.

Meanwhile the Iranians have made huge sacrifices, cutting back massively on their civil nuclear capacity while agreeing to an inspection regime which is far more intrusive than any country has ever agreed to before.

There remain significant obstacles to be surmounted before the deal is finally signed off. Nevertheless there is a better than 50 per cent chance that the agreement will ultimately be consummated. If that happens it will be a glorious moment in global diplomacy.

In terms of geo-political significance, it bears comparison to President Richard Nixon’s visit to China in 1972. This is because Obama has charted a new direction. For the past two decades, Amercian foreign policy has been based on a primitive understanding of the world.

American leaders have divided foreigners between good guys and bad guys, an approach that has led to disasters in Afghanistan, Iraq, Syria, and the wider Middle East.

Of course, there are all kinds of concerns about Iran: its dismal treatment of domestic political opponents, its appalling human rights record, its sponsorship of terrorism. For the past 30 years, all of this has given the United States an excuse to treat Iran like a pariah state.

Obama has returned the United States to a wiser and more sophisticated statecraft, which approaches the world in terms of different shades of grey, rather than black and white. The President has also turned his back on a world view that has led the United States into a narrow set of Middle Eastern alliances: Saudia Arabia, the Gulf States, and Israel. It is essential to note that the President isn’t turning his back on old friends. He is taking into account the other side as well.

This is sensible because none of the problems of the Middle East can be solved without the active assent of Iran. Islamic State cannot be defeated, the Syrian civil war cannot be solved, and America cannot withdraw peacefully from Afghanistan.

The Iranians have often offered assistance to the United States in the past. They did so after 9/11, and before the Iraq invasion. In 2003, before a single centrifuge was running, they offered a comprehensive settlement.

On each one of these occasions, President George W. Bush rebuffed these advances, with disastrous consequences. Obama and John Kerry deserve enormous credit for pushing forward these negotiations in the face of concerted opposition from domestic opponents as well as many of America’s closest allies.

Barack Obama was awarded the Nobel Peace Prize in the first year of his presidency, when he had achieved nothing. Six years later, the President has at last achieved pulled off an international deal which actually merits the accolade.

It is not clear whether the Nobel Prize can be awarded twice. Nevertheless, the world is a much safer place than it was this time last month.

Kerry and Iranian Foreign Minister Mohammad Zarif will be exceptionally strong candidates to share the prize this year. They have laboured flat-out for 18 months to achieve the impossible.

They have struck a blow for non-proliferation. They have taught the world that diplomacy rather than war can offer a solution. They have headed off the prospect of an Iranian nuclear bomb. Though Benjamin Netanyu would be reluctant to admit it, they have helped secure the long term security of Israel. Zarif has helped to bring Iran back into the comity of nations. Kerry has done the same for the United States.

The Lausanne agreement is the most hopeful moment in world affairs since the fall of the Berlin Wall. Let's hope and pray that it will not be undermined in the months ahead.