After the dramatic cruise missile and drone attacks on Saudi oil facilities at Abqaiq and Khurais on Sept. 14, the provocations by Iran and its proxies against Saudi Arabia and regional shipping have ebbed. And with the Trump administration choosing to avoid direct military retaliation against Iran — even after pointing the finger of blame squarely at Tehran for the September attacks — the Saudis have backed away from their sharply confrontational stance toward Iran in favor of seeking dialogue to reduce tensions.

In the larger contest, Iran and the United States ultimately want to avoid an escalation that could ignite a military conflict, yet Tehran has every reason to continue pressuring Washington to abandon its "maximum pressure" campaign of sanctions, meaning the two remain on a collision course. For one, Iran's announcement on Nov. 4 that it would take additional steps to abandon some of its obligations under the Joint Comprehensive Plan of Action (JCPOA) — known colloquially as the Iran nuclear deal — has put it on the road toward reactivating its more advanced centrifuges, accumulating light enriched uranium at a quicker pace and reversing the conversion of the hardened facility at Fordow to non-enrichment purposes. As a result, concerns about a reduction in Iran's breakout time (the time needed to enrich uranium into fissile material to produce one nuclear warhead) could resurface by the spring — and easily precipitate a crisis by summer. What's more, Iran's installation of ballistic missiles in Iraq, Syria and Lebanon to target Israel, as well as the increasing frequency of attacks by Iran-backed Iraqi militias against U.S. forces in Iraq, could provoke retaliation by the United States or Israel that easily sets the region on the path toward war.

Farewell to the JCPOA?

Of the Arab Gulf states, Saudi Arabia, Bahrain and the United Arab Emirates have long maintained the most confrontational stances toward Iran, and all remain deeply concerned about Iranian hegemony in the Middle East and the Persian Gulf. But given the severity of the Abqaiq attack, the existence of several triggers that could ignite a regional conflagration, and Riyadh's and Abu Dhabi's inability to control how Israel and Washington handle Iran, it makes sense for these wary Arab Gulf powers to pursue dialogue with Tehran that could de-escalate tensions across the Persian Gulf. As it is, Saudi Arabia is focused on attracting foreign investment in the coming year, meaning it deeply desires stability in the Persian Gulf. For Iran, too, pursuing dialogue could also help disrupt nascent ties between Israel and Arab Gulf countries.

Saudi-Iranian tensions, however, aren't the only possible trigger of an escalation in the Middle East, as Tehran still hopes to pressure the United States into granting some sanctions relief by slowly walking away from its JCPOA commitments. Until recently, Iran had trodden carefully, taking modest steps to avoid giving the United States and Israel reason to take action over quicker breakout schedules or Europe reason to invoke the JCPOA's dispute resolution mechanism or withdraw from the treaty.

Between Nov. 4 and 6, however, Iran signaled that it would pursue more brinksmanship with the United States by expanding the pace at which it produced enriched uranium and renewing work on more advanced enrichment centrifuges. As a result, Iran could substantially reduce its breakout time by next summer — something that Iran hawks in the United States will hardly tolerate.

Specifically, Iran has begun accumulating enriched uranium from more advanced IR-2, IR-4 and IR-6 centrifuges at Natanz. Furthermore, it has informed the International Atomic Energy Agency (IAEA) of its intention to resume testing and development of more advanced IR-7, IR-8 and IR-9 centrifuges. (According to the JCPOA, Iran could only conduct research on new designs for such centrifuges using computer modeling.) If testing proves successful, these newer centrifuges could sharply reduce breakout time if they begin processing uranium hexafluoride gas. The Islamic republic has also activated older IR-1 centrifuges at Fordow, where the JCPOA does not permit Iran to process uranium.

According to Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, these new violations of the JCPOA have raised Iran's production of light enriched uranium from 450 grams per day to 5 kilograms per day. As many nuclear experts have observed, that rate of production could bring Iran from its current 372-kilogram stockpile to the roughly 1,050 kilograms required to achieve breakout as early as April 2020. Ultimately, the breakout time will depend on the overall throughput capacity of Iran's enrichment complex, which it could expand further if it deploys additional advanced centrifuges. Many U.S. policymakers, including Democrats who were critical of the Trump administration's withdrawal from the JCPOA, would consider a breakout time of a couple of months to be a crisis — and that's even without Iran moving to enrich its uranium to weapons-grade or halting the IAEA's monitoring work.

Salehi, moreover, said Iran intended to announce another round of departures from the JCPOA around Jan. 5, including moves that could reduce the breakout time by raising the maximum level of enrichment from the current 4.5 percent, deploying more advanced centrifuges or both.

While the JCPOA's European signatories (Germany, France and the United Kingdom) have not invoked the pact's dispute resolution mechanism, they are likely to do so in the first half of 2020 — possibly as early as next month if Iran makes a significant move. Absent negotiations between the United States and Iran, this action could formally kill off the JCPOA, meaning the only mechanism that would constrain Tehran's nuclear development would be the Nuclear Non-Proliferation Treaty, which permits countries to reduce the breakout time to the minimum without violating the pact.

Mediation efforts by both French President Emmanuel Macron and Japanese Prime Minister Shinzo Abe have continued behind the scenes in recent months, but there are few signs of movement from Washington or Tehran toward a compromise (or capitulation) that would facilitate direct negotiations. And with U.S. President Donald Trump facing both a looming impeachment trial in the U.S. Senate and a reelection campaign, it may be harder for the White House to focus on finding an exit from a path that could result in a crisis by summer — the president's desires to avoid a hot conflict notwithstanding.

The Israeli Factor

Equally, Iran's buildup of proxies and missiles in Iraq, Syria and Lebanon could bring the region closer to war, especially as Israel will move independently to restrain Iranian influence when it clashes with its interests. As it is, Israel is already engaged in an aggressive airstrike campaign in Syria and, since the summer, Iraq and Lebanon. The Israeli military has sought to diminish Iran's ability to use long-range missiles to threaten Israel and impose a high cost on Iran for its military buildup in these countries.

Each country has a different escalation pattern; Lebanon, for example, is one of the most sensitive areas for Iranian buildup. This is, in part, because Iran's Lebanese proxy, Hezbollah, is Tehran's most capable, and Israel is concerned about the impact of a full-scale conflict. Accordingly, Israel is countering Iranian interests in Lebanon with greater restraint than in Syria or Iraq. In next-door Syria, the buildup is provocative but less likely to escalate into a regional war, as Israel's strikes on Iranian forces have become part of the pattern of their ongoing confrontation, and Tehran has decided to endure the campaign rather than trigger a regional war. Moreover, the Syrian government remains weakened by the civil war, and Israel's yearslong bombing campaign has disrupted Iran's buildup, making it less likely that Damascus and Tehran can readily strike back as effectively against Israel.

Finally, in Iraq, the Iranian military expansion has now prompted some Israeli airstrikes against Tehran's ballistic missiles in the country, leading Iraq's Popular Mobilization Units (PMUs), many of which have links to Iran, to look for ways to retaliate against Israel or its American ally. Such retaliation could injure or kill U.S. forces, touching off a tit-for-tat escalation — particularly after U.S. Secretary of State Mike Pompeo told Iraqi leaders in June that the killing of Americans would cross Washington's red line. As it is, American bases have come under harassment by still unverified forces, prompting at least one instance of reported U.S. retaliation against the PMUs. After a Dec. 3 attack on Iraq's Ain al-Asad base, for instance, U.S. forces reportedly assisted with the arrest on Dec. 19 of a PMU commander allegedly linked to the attack. Ultimately, because PMU retaliation could drag the United States into the fray — and because Iran's buildup remains in its infancy — Israel has shown some restraint recently in conducting strikes in Iraq.

The Upshot

The trajectories of both Iran's nuclear development activities and its actions in Iraq and the Levant suggest that the lull in tensions since the Abqaiq and Khurais attacks are about to come to an end. All parties want to avoid a conflagration, but Iran is feeling empowered by its perception of U.S. weakness, meaning both of these tracks present increased dangers in 2020. The nuclear track risks will increase over time unless the countries can find an exit — although Iran could spring a surprise at any time, plunging the region into conflict.