Iran’s stated willingness to restrain its disputed nuclear programme is sure to leave a lasting impact on the region. Iranian President Hassan Rohani said last week at the World Economic Forum (WEF) in Davos that his country is determined to negotiate a comprehensive deal so it can develop its battered economy.

The six-month deal reached in Geneva between Iran and the P5+1 (the five permanent members of the UN Security Council, plus Germany) on November 24 offers Iran about $7bn - equivalent to 20% of Iran’s budget deficit - in sanctions relief in exchange for curbs on its nuclear programme.

In fact, Tehran seemed desperate for the deal that took effect on January 20. Global sanctions spearheaded by the US have cut Iranian’s crude sales by 60% since the start of 2012, depriving the country of more than $80bn. A steep drop in net oil-export revenue, from $95bn in 2011 to $69bn in 2012, was catastrophic for a country whose oil sales comprise 80% of export earnings and 50% of government revenue.

With the interim deal in effect, experts say an eventual easing or lifting of sanctions can open up enticing prospects for global firms. With its population of 75mn, Iran would be the largest economy to rejoin the global economic system since post-Communist Eastern Europe in the early 1990s.

Interestingly, though Russia had joined the West in imposing some Security Council-approved sanctions on Iran, Moscow didn’t sign on to the majority of Western sanctions. Russian companies might have an edge in Iran if peace leads to a fresh commercial boom.

But despite the euphoria, here is the flip side.

The interim deal will still allow Tehran to continue far more research and development to enrich uranium than has been publicly recognised, according to David Albright, a veteran Washington-based nuclear analyst.

Despite Rohani’s charm offensive, statements made by the Iranian leader and his top aides at the WEF rekindled concerns about his ability to deliver. Neither did Rohani, nor his foreign minister, Javad Zarif, convey a willingness to accept a substantial dismantling of Iran’s nuclear infrastructure. “In the context of R&D and peaceful nuclear technology, we will not accept any limitations,” Rohani told CNN in Davos.

Iran has long made clear its ambition to become a major regional - and indeed global - power. That ambition can only grow stronger with the economic gains resulting from increased flow of foreign investment into the country.

Iran’s efforts to develop nuclear weapons pose a huge danger, and, if left unchecked, are likely to trigger a wave of proliferation across the Middle East, says Turki bin Faisal al-Saud, who served as the director general of Saudi Arabia’s intelligence agency from 1977 to 2001, and as Saudi’s ambassador to the UK and the US.

Qatar did welcome the Geneva deal. Qatar’s Foreign Ministry last November called the agreement “an important step towards safeguarding peace and stability in the region”.

Iran now has to respond with concrete confidence-building measures. Building trust, especially with its immediate neighbours, is key to Iran’s sustainable growth and prosperity in a globalised economic system. For that, Iran has to take the extra step to walk beyond the interim nuclear deal.

A nuclear-free Middle East is a must to ensure lasting peace and prosperity in the region.