Ordinary Iranians the big winners in groundbreaking nuclear peace pact
The images from Tehran after news broke of an historic deal on Iran's nuclear programme this week told their own story. Exuberant crowds took to the streets, cheering and dancing in celebration of an agreement that means their nation will now come in from the cold of international sanctions.
Many carried a large, wooden key, the symbol of president Hassan Rouhani's election campaign two years ago, during which he put a nuclear deal on the top of his priority list.
The accord announced in Vienna was the fruit of 19 days of intense negotiations and four missed deadlines. It is designed to contain Iran's nuclear programme, which Tehran has long insisted is only for energy purposes, for at least a decade, and will involve more comprehensive UN inspections to monitor its nuclear facilities.
As part of the deal, Tehran will get relief from the international sanctions that have crippled its economy for almost 10 years. The agreement is not only a victory for Rouhani, it is also a vindication of US President Barack Obama's policy of engagement and marks Washington's first real success in dealing with Tehran since the seizing of the American embassy there in 1979.
Anyone who has visited Iran in recent years will know how much sanctions have affected ordinary Iranians. Isolation from the international banking system and the loss of oil revenues have caused Iran's currency, the rial, to plummet by two-thirds of its value against the dollar since sanctions were tightened in 2011.
Inflation has soared and the prices of fuel and basic foodstuffs have rocketed. Some estimates hold that the most recent round of sanctions brought Iran's GDP down by 20pc and contributed to a jobless rate of 10.3pc, hitting young Iranians the hardest.
Between 2009 and 2013, more than 300,000 Iranians emigrated in search of better prospects elsewhere, and today, 25pc of Iranians with a post-graduate education are to be found living and working outside Iran.
By some estimates, the re-entry of Iran to the global marketplace means its economy will grow to more that 5pc GDP within a year. With the fourth-largest crude oil reserves in the world, the end to sanctions means Iran could increase its production to around 4pc of global output within months, thus lowering oil-price forecasts by $5-$15 per barrel.
The reopening of Iran and its consumer market of 78.5 million people means there will be a flurry of interest from investors. The country's creaking infrastructure - particularly in its energy sector - means it needs all the help it can get.
Before sanctions were tightened in recent years, Iranians had courted Ireland's construction sector, hoping Irish companies could help address its chronic housing shortage.
In addition to the boost to its economy, the lifting of sanctions means Iran will now be able to reclaim more than $100bn of its oil revenues, locked until now in foreign banks.
Critics of the Vienna accord argue, however, that an Iran newly flush with such funds could mean more instability for the Middle East if it uses the monies to aid its allies, including Syrian President Bashar al-Assad, Hizbullah, the Houthis in Yemen, and various Shia militias across the region.
Not surprisingly, Saudi Arabia and Israel have been the most opposed to a deal with Iran. Not only does Saudi Arabia stand to lose significant market share as Iran re-enters the global oil market, it also faces an upping of the existing regional power-play as Tehran begins to shed its international pariah status.
The worry in Riyadh and other predominantly Sunni capitals is that this, in turn, will further fuel sectarian conflicts across the region.
Israeli Prime Minister Benjamin Netanyahu and his right-wing government were always set against any compromise with Tehran that would allow it to continue enriching uranium as the Vienna deal does. But Israel finds itself isolated in its position, with its greatest ally now recognising and engaging with Tehran as an important interlocutor in the region.
While the agreement does not mean diplomatic relations will be restored or Washington will shy away from criticising Tehran's support for militant groups and its human rights abuses at home, it may usher in some form of coordination in relation to the battle against Islamic State in Iraq.
US air strikes alone will not be enough to push IS back there and Iran's influence in Iraq is key. Syria- and Iran's role in propping up Assad - is more complicated but optimists argue there may now be space for dialogue with Tehran on how to resolve the crisis or at least address the humanitarian fallout.
But the biggest winners from this week's groundbreaking deal are the millions of ordinary Iranians who longed to see an end to their country's isolation.
As one told me on a visit to Tehran some years ago: "We want to be part of the world, not apart from it."