The achievement of “implementation day” of the Joint Comprehensive Plan of Action (JCPOA), when for both sides the central elements of the nuclear bargain went into operation on Saturday, means that it is going to be a fact of life in global and regional politics for many years. But will it have a profound impact on regional politics?

That is the argument both the Barack Obama administration and US allies in the Middle East who have opposed it have made in the past.

While Washington has said the agreement makes it more likely that Iran will eventually come to terms with its neighbours, Israel and Arab states have advanced precisely the opposite forecast, suggesting it will inevitably cause Iran to be far more aggressive and uncompromising.

However, especially in light of the dramatic deepening of the conflict between Iran and Saudi Arabia over the past year, it is now clear that focusing solely on whether it will reshape Iran’s policies is the wrong way to define the problem. Far more important is whether the agreement will create the impetus for realignment of US policy in the region.

Both sides have used their arguments as devices to advance their political interests rather than offering serious political analysis.

The Obama administration has argued that by closing off the pathways to an Iranian nuclear weapon, the agreement opens up the possibility of domestic and foreign policy changes in Iran.

In perhaps the most far-fetched expression of that argument, Secretary of State John Kerry suggested in an interview with Reuters last August that Iran’s Islamic Revolutionary Guard Corps had been “counting on this nuclear thing to give them the umbrella of protection over their nefarious activities, and they object to this precisely because it takes that umbrella away".

That was a poorly conceived self-serving argument: the imagined possibility of having nuclear weapons in the future was totally irrelevant to IRGC involvement with Hezbollah in Lebanon, or to its presence in Iraq and Syria.

The Israelis and Saudis, on the other hand, have insisted that the nuclear agreement would empower the Iranians to be far more interventionist in the region as well as to continue to seek nuclear weapons. The Israelis pushed the idea that Iran would use the additional income gained from lifting sanctions to fund Hezbollah or the Syrian government, making the region more unstable and more threatening to Israel.

Yet the Iranian support for Hezbollah is a fundamental national security investment that has never depended on any additional infusion of resources from the nuclear deal. In fact, the commitment to support Hezbollah troops in Syria was taken in 2012, well before the nuclear negotiations had even begun.

Both Israeli and Saudi officials have suggested that the Obama administration’s negotiation of the agreement represented a decision to fundamentally alter its alliance policy by entering into a quasi-alliance with Iran.

The Saudis have carried that theme to a much greater extreme. As F Gregory Gause wrote in late 2013, the Saudis were already expressing the fear that the United States would “ratify Iranian hegemony in Iraq, Syria, Lebanon and the Persian Gulf in exchange for a nuclear deal”.

The Saudi fear of an entente between Washington and Tehran may have deepened since the agreement was reached, but Saudi fears of US acquiescence in a regional distribution of power - which Riyadh has found unacceptable - are not really about the nuclear deal itself; rather, they centre on Saudi unhappiness with the failure of the United States to go to war in Syria.

Similarly the Israeli objection to the nuclear deal was ostensibly that it wasn’t really going to end Iran’s quest for nuclear weapons. However, what the Israelis really wanted was to reduce Iran’s military and economic power, either through military confrontation between the United States and Iran or through crippling sanctions.

The agreement represents the ultimate failure of that long-term Israeli strategy, but that has nothing to do with the longer-term issues and forces at work in the region.

The agreement is clearly not going to influence regional politics by depriving Iran of nuclear weapons that Iran has had no intention of obtaining anyway. The real issue is whether the process of negotiating has created a new US-Iran political dynamic that can influence the outcomes of the conflicts in Syria, Iraq and Yemen.

That is what both the Obama administration and the Rouhani government appear to be hoping for. US Secretary of State John Kerry and Foreign Minister Javad Zarif both suggested that the new relationship helped to quickly resolve the incident involving two US Navy ships that sailed into Iranian waters.

Even so, it is highly doubtful that the agreement will have a very deep impact on US policy in the next few years or affect any of the intertwined conflicts that are reshaping the Middle East.

US policy toward Iran is the product of decades of constant anti-Iran news, official pronouncements and opinions. The idea of Iran as an aggressive threat to US interests has become deeply embedded in the country’s electoral and bureaucratic politics.

That assumption has been translated into laws and programmes that have created new institutional interests in maintaining the status quo. Not the least of those interests is that Iran has long served as the primary rationale for the US military presence and role in the Middle East, as well as for the sale of weapons and anti-missile systems to regional allies.

Iran has also long become a major focus – if not the leading target - of CIA and National Security Agency spying efforts worldwide.

Obama’s apparent view that Saudi Arabia can serve as a partial substitute for direct US military operations in order to combat terrorism and Iranian influence in the region has added yet another obstacle to the realignment of US regional policy.

Six months after the nuclear agreement was first signed in July 2015, Obama has shown no willingness to break openly with the Saudis on Syria or Yemen, despite the recklessness of Saudi policies in those countries.

The recent moves by the Saudis to raise tensions with Iran suggest that the Saudis are still hoping to force the Obama administration into a more aggressive anti-Iran posture in the region. That may well fail, and in the long run the US may well adopt a more even-handed posture toward Iran to deal with the chaos that has descended on the region.

If and when that happens, the nuclear agreement will not have loomed very large in the decision.

- Gareth Porter is an independent investigative journalist and winner of the 2012 Gellhorn Prize for journalism. He is the author of the newly published Manufactured Crisis: The Untold Story of the Iran Nuclear Scare.

The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Eye.

Photo: US Secretary of State John Kerry (C) speaks with Iranian Foreign Minister Mohammad Javad Zarif (R).