Iran is as close as it’s ever been to seeing relief from sanctions that have crippled its economy for decades. The agreement reached Thursday between six world powers and the Islamic Republic over its nuclear capabilities could allow the country to “rejoin the community of nations,” U.S. President Barack Obama said.

The deal struck in Lausanne, Switzerland, between the P5+1 group of nations, led by the U.S., and Iran came at a time when the Tehran regime finds itself aligned with Western interests on the most pressing issue in the Middle East, the rise of the Islamic State group. Iran and the U.S. are fighting on the same side against the group -- also known as ISIS or ISIL -- while Iran continues to expand its reach in the region.

The agreement creates opportunities for Iran, which, in the long term, could help it solidify its position as the rising power in the Middle East, experts said. But, at home, the opening up to commerce and the world that may come with sanctions relief could, ultimately, weaken the Iranian regime.

'De-escalate The Confrontation'

The Iranian government was pushed to an agreement by “the need to de-escalate the confrontation with the U.S., in particular to get out from underneath the sanctions,” said J. Matthew McInnis, a former senior analyst at the U.S. Defense Department and a current resident fellow focusing on Iran at the American Enterprise Institute, a public-policy think tank based in Washington. “That’s been a fundamental calculation in the past two years.”

Thursday’s framework agreement is just the first step toward a deal between Iran and the P5+1 group (consisting of the five permanent members of the United Nations Security Council plus Germany). Negotiations on details of Iran’s nuclear facilities, a timeline for sanctions relief and monitoring requirements will be announced only in the event a final deal is reached by the end of June. With the lifting of the sanctions imposed by the U.S. and European Union, Iran would be able to leverage its economic size to gain further political clout.

“Sanctions relief makes some difference to Iran’s standing in the world,” said James M. Acton, co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace, a foreign-policy think tank headquartered in Washington. “What countries in the region are afraid about -- exaggeratedly, in my opinion -- is much more that the U.S. will turn to Iran as its partner in the region at the expense of Sunni states.”

Iran has been able to expand its reach in the region largely through arming and funding Shiite militant groups. The Iranian regime is a key player in the fight against the Islamic State group in Iraq and Lebanon, a powerful force behind Houthi rebels in Yemen, and the strongest supporter of President Bashar Assad’s regime in Syria. In all those countries except Iraq, the U.S. has stated that Iran’s involvement is worrisome and has backed the opposing side of the conflict.

“Iran tends to overestimate how effective it can be,” McInnis said. “Iran is growing in strength in Iraq, Syria, Lebanon and Yemen, but it creates a backlash which fuels sectarian tensions, which groups like ISIS exploit.”

Solution Needed

Before any strategic calculation, however, the Iranian government may have been pushed to an agreement by the need to re-enter the global economy and get rid of crippling sanctions, which have excluded Iranian banks and other firms from the international financial circuit and made it almost impossible for Iran to export and import legally. Plummeting oil prices -- Iran is the world’s sixth-largest oil producer -- have helped sink its economy, which contracted by a staggering 25 percent from 2013 to 2014. Clearly, the regime in Tehran needed a solution to its problem quick.

Iranian Supreme Leader Ali Khamenei and President Hassan Rouhani realized they had to “start fixing some of these long-term problems,” McInnis said. Otherwise, they would “risk having Iran being much weaker in the region and even having greater domestic instability, which is the supreme leader’s greatest nightmare.”

That short-term solution may turn out to be a long-term headache for Iran’s theocratic regime. Greater openness may turn increasing numbers of Iran’s young, politically active population away from the regime: About 60 percent of Iranians are under 30 years old, and many have already engaged in mass demonstrations from 2009 to 2012, first in response to a controversial presidential election, then in solidarity with other protest movements across the Middle East.

Meanwhile, Acton said, “If there is a deal and the U.S. abides by it, that could go a long way to undermining the Islamic Revolution.”