VIENNA (AP) — Overcoming decades of hostility, Iran, the United States, and five other world powers struck a historic accord Tuesday to check Tehran's nuclear efforts short of building a bomb. The agreement could give Iran access to billions in frozen assets and oil revenue, stave off more U.S. military action in the Middle East and reshape the tumultuous region.

The deal sets in motion a years-long test of Iran's willingness to keep its promises to the world — and the ability of international inspectors to monitor compliance. It also sets the White House up for a contentious fight with a wary Congress and more rocky relations with Israel, whose leaders furiously opposed the agreement.

Appealing to skeptics, President Barack Obama declared that the accord "offers an opportunity to move in a new direction. We should seize it."

Under terms of the deal, the culmination of 20 months of arduous diplomacy, Iran must dismantle much of its nuclear program in order to secure relief from biting sanctions that have battered its economy. International inspectors can now press for visits to Iran's military facilities, though access is not guaranteed. Centrifuges will keep spinning, though in lesser quantities, and uranium can still be enriched, though at lower levels.

In a key compromise, Iran agreed to continuation of the U.N.'s arms embargo on the country for up to five more years and ballistic missile restrictions for up to eight years. Washington had sought to keep the arms ban in place, while Russia and China joined Iran in pushing for an immediate suspension.

On the streets of Tehran, Iranians honked their horns and celebrated in the city's main square. President Hassan Rouhani said a "new chapter" had begun in his nation's relations with the world, even as he denied Iran had ever pursued a nuclear weapon.

While the U.S. partnered in the talks with Britain, France, Germany, Russia and China, the decades of tensions between the U.S. and Iran put the two countries at the forefront of the negotiations.

Whether the nuclear rapprochement will spark a broader thaw is unclear. Nearly 40 years after Iran's Islamic revolution and the hostage-taking at the U.S. Embassy in Tehran, the country's hardliners remain hostile toward Washington. The U.S. and its allies also have deep concerns about Iran's support for terrorism in the Middle East and its detention of several American citizens.

David Fuller's view

Potentially, this is a hugely important agreement and I recommend that anyone interested in this topic watch this full video of President Obama’s speech on the Iran nuclear deal. You can also read his speech.

The risks in trusting Iran to honour this agreement are well known, but monitoring is possible and UN inspections will occur.  Moreover, flush with cash, Iran could easily finance further military turmoil in the Middle East and beyond. 

Nevertheless, we should try to view this agreement from Iran’s perspective in 2015.  If a country is widely condemned as a pariah state, it is easier to behave like one.  Fortunately, the world is no longer dealing with Ayatollah Ruhollah Khomeini.  Iran’s current supreme leader, Ayatollah Ali Khamenei is less of a firebrand and also elderly.

To paraphrase Mrs Thatcher following her comments on Gorbachev: we can do business with Iran’s President Hassan Rouhani.  Moreover, what would Iran gain by using nuclear weapons, assuming it eventually built them, relative to the downside of potential annihilation? 

Moreover, Iran has a comparatively well educated young population.  Iran will not halt its military activities in the Middle East just because of a nuclear power agreement, but somewhat ironically, it is currently an ally of the USA in the war against the so-called ISIL.  More importantly, Iran has much more to gain from peaceful economic development within the international community than from funding terrorism.

President Reagan, with the advice of Prime Minister Thatcher, found that he could do business with Soviet President Gorbachev, helping to end the Cold War.  Today’s Republican Senators and members of Congress may wish to recall this rather than automatically opposing the Iran deal because it occurred thanks to President Obama’s initiative.

Might there be a peace dividend from the Iran nuclear deal?  Yes.  The first benefit would be extra oil supplies commencing next year, helping to keep the price down.  Over the longer term, a developing, preferably peaceful Iranian economy would be good for the global economy.  Trade with the West would certainly increase. 

(See also: Iran Return From Exile Poses a Challenge for U.S., Allies)