The agreement between Iran and the P5+1 is a potentially crucial milestone in nuclear proliferation and arms control. The hard work of transforming general principles into a detailed final agreement may yet prove impossible and will probably take longer than the June 30 deadline. If a comprehensive deal is agreed on later this year, it will significantly reduce the risk of further proliferation in West Asia.

The agreement reached in Switzerland left many crucial details to be addressed in the next round of talks. The vital details of the inspection regime are still to be worked out. The most difficult issue will probably be the sequencing of sanctions-relief. Iran wants the UN and EU sanctions removed early. These are the most damaging because they are multilateral. The Iranians, who joyously greeted the announcement from Lausanne, expect rapid relief. Anything prolonged will disappoint.

Washington wants conclusive proof of Iranian compliance with the nuclear inspections and limitations on Iran’s programme in place and working before substantial sanctions-relief. It wants relief hinged on automatic reimposition if Iran blocks inspections, a snap-back provision that would deter cheating.

Unilateral US sanctions can be suspended by the president if they are linked to the nuclear weapons issue alone. But most are linked to Iran’s support for terrorism as well and thus cannot be suspended without Iranian actions on that front, which is highly unlikely.

Already, the gap between the parties is emerging in their efforts to garner domestic support for the Lausanne deal. Each is spinning the results selectively. This is to be expected but will be exploited by the deal’s opponents, especially Israel.

Israeli Prime Minister Binyamin Netanyahu has staked his political legacy on fighting the deal. He lobbied against it in the US Congress and campaigned against it to win re-election. This is the biggest and most public fight ever between an American president and an Israeli prime minister. It will shape the bilateral relationship for years to come. The longstanding bipartisan support for Israel in American politics could become a partisan issue, with Republicans backing Netanyahu and Democrats with the president.

Of course, the prime minister makes no mention of Israel’s own nuclear arsenal. The fact that Israel has dozens of nuclear weapons and can deliver them by aircraft, missiles and submarine-launched cruise missiles is rarely mentioned in the American debate on Iran. If a deal with Iran is secured, international attention on the Israeli arsenal is certain to grow. Egypt has long been pushing for more debate about Israel’s programme.

All seven parties (Iran and the P5+1) want a final deal and are now invested in a positive outcome. None of the parties, especially not Tehran or Washington, wants a war, which is the alternative to a negotiated deal. US President Barack Obama has ruled out containing Iran. So, he has no fallback except military force if talks collapse and Iran proceeds to build the bomb. Netanyahu has not proposed a viable alternative.

If a deal is reached, it will significantly reduce the risk of further proliferation in the Middle East. Saudi Arabia, the other major critic of a deal, has only one viable way to get a bomb. Given the weak Saudi nuclear infrastructure, it would have to get the bomb from Pakistan. Rumours of such a secret deal have been stoked by Riyadh and Islamabad for years. Both see virtue in the spectre of a secret nuclear deal, which they can always publicly deny.

But an Iranian commitment not to proceed in developing a nuclear-weapons arsenal, backed up by tangible constraints and inspections, will make a Saudi-Pakistani arrangement unnecessary.

Moreover, the war in Yemen has already raised serious doubts about any putative Pakistani commitment to provide a bomb to Riyadh. In the past, Saudi leaders have privately hinted that Pakistan owed them the bomb for decades of past economic and political support. But when Saudi Arabia actually went to war with what it describes as an Iranian protege — the Houthi rebels in Yemen — Pakistan failed to provide any tangible help for Operation Decisive Storm.

Although he has promised to support Saudi territorial integrity and independence, Pakistan Prime Minister Nawaz Sharif rebuffed Saudi King Salman bin Abdulaziz’s requests for ground forces, and so far has not even participated in the air war in Yemen. If a Pakistani politician like Nawaz, who spent years in exile in the kingdom, won’t provide conventional military help for a struggle with Iran, a secret bomb deal is highly doubtful. In any case, a comprehensive nuclear agreement with Iran, ratified by the UN Security Council, would make the issue irrelevant.

Obama has invited Salman and other Gulf monarchs to Camp David to persuade them to support a final deal. The president has invested much time in building a relationship with Riyadh. Support for Operation Decisive Storm in Yemen has been deeply appreciated by Riyadh and is likely to increase as the Saudis need more intelligence and logistical support.

A nuclear deal will not lead to a broader American rapprochement with Iran. Although some in America may hope for that, and the Israelis and Saudis fear it, powerful parties in Iran will block any movement toward normalising ties with the Great Satan. The Revolutionary Guards and powerful mullahs are determined to continue to arm and support groups like the Houthis and Hezbollah, as well as the Bashar al-Assad regime in Syria and the Shia militias in Iraq. Ayatollah Khamenei, the supreme leader, is their patron.

Nonetheless, once sanctions are lifted, foreign investment and business will come to Iran in volumes not seen since the revolution in 1979. Iran will be more open to outsiders than it has been in decades. That is precisely what the Iranian hardliners fear and the reformers favour.

Obama faces a complex dynamic with Iran. While negotiating with the other five on the nuclear front, he is also backing the Saudi-led war in Yemen against Iran’s Houthi ally and fighting alongside Iran in Iraq against the Islamic State. In Syria, Iran backs Assad and America wants him gone. This is an extraordinarily intricate diplomatic playing field to manage. It will test Obama’s ability to articulate the subtleties of his foreign policy to Congress, the American people and the world.

This piece was originally published by The Indian Express.