A nuclear deal with Iran depends on President Obama’s ability to sell any Iranian nuclear agreement to the US Congress.

Suspending 20 percent uranium enrichment, extending inspections at the 3.5 percent level, and bringing any other longer-term proliferation risks into a robust nuclear agreement with Iran (i.e. the yet to be built nuclear reactor at Arak) is one thing, but building confidence between the West, Gulf Cooperation Council (GCC) states and Iran across a range of contentious geo-strategic issues is quite another.

Yes, a nuclear deal will be a welcome breakthrough and could herald a paradigm shift in drawing the US and Iran to negotiate directly on other issues, from Afghanistan to Syria, but could such engagement be sustained amid a tacit alliance between Saudi Arabia, Israel and the US Congress dead set against diplomatic progress with Iran?

That depends on President Obama’s ability to sell any Iranian nuclear agreement to the US Congress.

The President’s ability to persuade King Abdullah of the merits behind dealing with what the US government has long labeled a “state sponsor of terrorism,” part of the “axis of evil” and as having been working conscientiously to obtain a nuclear weapon for years, is likely to be limited. Reconciliation is possible, but Saudi Arabia and Iran are engaged in an unprecedented sectarian struggle across the region which has been exacerbated by the Arab Revolutions.

Apart from which, the implications of a US-Iran rapprochement will have serious implications for the Kingdom. Saudi Arabia would immediately lose its de facto leadership position in the Middle East and therefore see the change in the stark terms of a zero-sum game. Iran wins. Saudi Arabia loses.

The US administration, therefore, needs to work hard on two fronts: developing a more active approach to Iran beyond the nuclear issue, while simultaneously addressing Saudi and GCC insecurities. These insecurities are also currently strengthening the Saudi-Pakistan bilateral relationship as Riyadh seeks a potential supplier of nuclear weapons should the P5 + 1 nuclear deal with Iran fail. By keeping Saudi Arabia in the loop, the US will be able to undermine some of the divisive sectarian issues and forces which are covering the region in a dangerous fog of conflict and uncertainty.

Another dimension is the Syria conflict; dealing with Iran on the nuclear issue is widely seen to be a necessary precursor to resolving it. However, any nuclear agreement with Iran will not solve the war.

Iran may be more predisposed to discussing its support of President Assad but due to the trust deficit that exists between Iran and the Gulf states, none of the latter will want to risk losing influence in Syria in case Iran reneges on any commitments. Keeping Saudi Arabia on board with US decision making and diplomatic outcomes is therefore vital.

Only by addressing the Iranian nuclear program and other contentions in a way which account for the variable concerns of all regional stakeholders can progress be made. The French exception during the P5 + 1 negotiations in Geneva has already illustrated this point.

In other words, since the hard slog of negotiations that address the gamut of linked national security threats in Iran, Israel and the GCC are yet to be addressed, it may be too early to assume a single nuclear agreement will be the golden bullet for regional peace. But if this active diplomatic approach is sustained, it could be part of a chain reaction which gets us to a new conference on a Weapons of Mass Destruction Free Zone in the Middle East (WMDFZME) and the roots of a post-Arab Spring regional security architecture.

Dr. Robert Mason is Lecturer in International Relations at the British University in Egypt and author of the forthcoming book Foreign Policy in Iran and Saudi Arabia: Economics and Diplomacy in the Middle East. Follow him on Twitter @Dr_Robert_Mason. Read other articles by Robert.