Washington CNN  — 

Deal or no deal in the Iranian nuclear talks, Tehran is already behaving like it’s made a killing.

Sure, U.S. and international sanctions have inflicted staggering damage on Iran’s economy, convincing the longtime American foe to join talks aimed at limiting its nuclear program. The negotiations faced a Tuesday deadline for a framework deal, but world powers announced late in the day that the discussions would continue into Wednesday.

But it’s not just Iran’s nuclear aspirations that have everyone’s attention – though just the fact that Iranian officials are at the table with the world’s most powerful countries has elevated Iran’s international status.

Getting the bomb would greatly magnify its regional – even global – role, but Tehran is also making big moves in a tumultuous Great Game of Middle East geopolitics that is challenging U.S influence and prestige and chilling Washington’s allies.

READ: Iran nuclear talks: ‘Tricky issues’ remain, Kerry says

As it engages on its nuclear program, Tehran has exploited the divisions of the Arab Spring and the power vacuum of America’s downgraded involvement in the region. It has also taken advantage of the leeway the United States offered in prioritizing a nuclear deal over attempts to restrain Tehran’s proxies that could risk breaking up the negotiations.

The result is that Iran – often through militant groups it sponsors – has become a key player in conflicts in neighboring states all the way to the edge of the Mediterranean.

Its drive for regional pre-eminence is becoming an increasing problem for the Obama administration as it contemplates selling a nuclear deal – which is already drawing considerable skepticism – to opponents in Congress and to anxious allies like Saudi Arabia and Israel, who are watching Iran’s maneuvering up close.

Critics are accusing President Barack Obama of turning a blind eye toward Iran’s nefarious motives and proxy wars in the Middle East to safeguard a legacy-enhancing push for a deal that could lift his presidency’s historic potential after decades of hostility between Washington and Tehran.

They fear Iran is not only about to walk away with a deal that leaves its nuclear infrastructure intact, but that it is also playing the United States for a fool by using the talks to shield its hegemonic ambitions in the Middle East.

“They have completely schooled the American and European diplomats,” said Michael Rubin, an Iran analyst and critic of the administration at the American Enterprise Institute.

“The Iranians used to brag that they play chess and we play checkers. It turns out that they play chess, while we play solitaire.”

Iranian proxies

Iran has used its Revolutionary Guard Corps and a host of proxies to fill the power gap left by the U.S. departure from Iraq and the political tumult stirred by the collapse of authoritarian governments felled by now-defunct popular reform movements.

“Iran was destined to expand its influence one way or the other, and the U.S. was not going to prevent that, especially because of the cost involved in trying to pacify Iraq,” said Reva Bhalla, vice president of global analysis at Stratfor, a global intelligence and advisory firm.

“Iran benefited from the Arab Spring as well.”

Iran has also seen an opportunity in the U.S.’s shifting policies and interests in the region. The George W. Bush administration pushed out the regional strongman in Iraq, Saddam Hussein, who kept Iran in check through a hostile balance-of-power arrangement. The subsequent collapse of the Iraqi state left a festering sectarian stew that Tehran was quick to use to forge links in Shiite areas.

And Obama, in addition to withdrawing American forces from Iraq, has sought a lighter touch in hot spots like Syria, Yemen and Libya, where chaos has created an opening for outside fighters and radical domestic groups to swoop in.

The regional meltdown that has seen governance collapse and national borders redrawn on sectarian lines has provided a potent breeding ground for radical, stateless Islamic groups — like ISIS – to grow and threaten both U.S. and Iranian national interests.

So the Obama administration also sees a common interest with Iran in fighting ISIS. But some critics say its desire to do so has blinded it to Iran’s activities elsewhere.

White House assessments

This has left the White House in the uncomfortable position of having to explain why the United States appears to be tacitly cooperating with Iran, with which it has waged a de facto ideological war for 30 years.

Senior U.S. officials deny they are going soft on Iran to keep Tehran sweet on nuclear talks. They say the negotiations are walled off from concerns about Iran’s aggressive moves elsewhere. And they point out that Tehran would be much more dangerous to its neighbors if it were able to build a bomb.

READ: Centrifuges and secret sites: Get up to speed on the Iran nuclear talks

“Even if a nuclear deal is reached, our concerns about Iran’s behavior in the region and around the world will endure,” White House Chief of Staff Denis McDonough told the J Street policy conference last week, slamming Iran as a state sponsor of terrorism, a proliferator and a gross violator of human rights that seeks to destabilize its neighbors.

Several U.S. allies in the region, watching Iran’s growing influence, worry that whatever berth the United States is giving Iran, it goes well beyond the nuclear talks and the fight against ISIS.

Instead, they fear the beginning of a wider détente with Iran that some are calling a “Persian pivot.”

Saudi concerns

Saudi Ambassador to the United States Adel al-Jubeir told CNN that Riyadh was “concerned about the interference by Iran in the affairs of other countries in the region, whether it is in Iraq, Syria, Lebanon, Yemen.”

Obama’s domestic foes are less diplomatic.

“I heard repeatedly from leaders in the region that they believe we are forming some kind of Faustian bargain with the Iranians which would then lead to great danger to those countries,” Republican Sen. John McCain of Arizona said last week.

“They believe that we are siding with Iran.”