The attacks appeared to involve cruise missiles and drones, and the apparent precision targeting cast serious doubt upon efforts by Yemen’s Houthi militants to claim responsibility for the damage.

That damage is estimated to have cut Saudi oil output roughly in half, preventing nearly six million barrels from reaching the market each day. As this constitutes roughly five percent of global oil supply, the attack has precipitated the largest single spike in crude prices since the outbreak of the Gulf War nearly 30 years ago. While it was initially reported that it would take a few weeks for the government-owned Saudi Aramco to recover from the incident, on Monday that figure was revised up to a period of months.

Naturally, this situation has prompted widespread discussion of a response from the US – a response that may be either wholly or partly military in nature. President Trump said via Twitter that the US was “locked and loaded,” but was waiting for input from the Saudis regarding how his administration should proceed. The tweet also noted that intelligence services had yet to verify the source of the attack, but neither the White House nor the Saudis wasted any time in announcing the likelihood of Iran being either the sole perpetrator or a participant in the attack.

It was not immediately clear why the Houthi would claim responsibility for the incident if the evidence failed to back this up. But it is well known that the Shiite militant rebel group has been backed by Iran since before it ousted the internationally recognized government of Yemeni President Abed Rabu Mansour Hadi in 2015. What’s more, the Washington Post reported on Monday that that backing has increased over time, as evidenced by the number and variety of weapons intercepted in the Arabian Sea since that time, which appeared to be en route from Iran to Yemen.

The ongoing Yemeni Civil War largely functions as a proxy conflict between Iran and Saudi Arabia, with the latter standing at the head of an Arab coalition that is actively fighting against the Houthi and working to reinstall the Hadi government. In the midst of that conflict, the Houthi have launched a number of missile attacks into Saudi Arabia, damaging pipelines and an airport but apparently doing little in the way of lasting damage. Last Saturday’s attacks were noticeably different, in ways that raised questions among experts about their real origins.

After leading White House officials met with the National Security Council, it was reported that the trajectory observed in the attacks did not support the Houthi assertion that they had come directly from Yemen. In addition, some of the fragments of the weapon recovered in Saudi Arabia seemed to bear hallmarks of Iranian manufacture.

New Grounds for Appealing to US Allies

The trend of pushing for multilateralism remained apparent in the midst of American responses to the new, more sophisticated attack on the US government’s greatest Arab ally. For example, Secretary of State Mike Pompeo said on Twitter, “We call on all nations to publicly and unequivocally condemn Iran’s attacks,” adding that the administration was prepared to work with its allies to make sure Tehran is held accountable.

Similarly, Energy Secretary Rick Perry said in an interview with CNBC on Monday, “It is a time for a coalition of tame and thoughtful energy-producing and energy-consuming countries to come together and put a stop to Iran’s malign activity.” References to such a coalition are already familiar to those who have been watching developments in the Trump administration’s strategy of “maximum pressure” on the Iranian regime. But these had previously been focused on the issue confronting Iran’s harassment of global shipping specifically.

The direct attack on Saudi energy infrastructure arguably exposes the extent of the damage Iran can do, either directly or with cooperation from its regional proxies, in a short period of time. But it remains to be seen whether this will make the international community more motivated to confront a range of potential Iranian threats than it has been to confront the specific threat of the Iranian Revolutionary Guards’ seizure and sabotage of commercial vessels near the Strait of Hormuz.

In May and June, a total of six tankers were apparently damaged by Iranian limpet mines. And the following month, the IRGC captured a British-flagged vessel in retaliation for British Royal Marines’ seizure of an Iranian supertanker, which was suspected being en route to Syria to complete a sale prohibited by European Union sanctions on the dictatorship of Bashar al-Assad. The ship, now known as the Adrian Darya 1, was released after about six weeks but went on to offload its oil in Syria anyway. Meanwhile, the British vessel, Stena Impero, remains in Iranian custody along with 16 of its crew of 23 crewmembers.

Despite all of this, the US has struggled to secure commitments from European allies for the “Sentinel Program” that has been promoted as a way to monitor the actions of the Revolutionary Guard and provide deterrent escorts to ships bearing the flag of participating countries. For a time, the coalition was limited to the US, the United Arab Emirates, and Australia. But the seizure of the Stena Impero may have contributed to the British government’s eventual decision, under new leadership, to sign on as well.

This change of policy and the underlying selection of Boris Johnson as British Prime Minister led to widespread speculation that the United Kingdom was moving closer to the endorsement of the US strategy of maximum pressure. That notion has also been broadened to include other European countries as Iran has taken provocative actions such as systematically halting compliance with the 2015 nuclear deal. Although the French government has led the way in trying to offer Iran incentives to reverse course, Paris recently declared that financial mechanisms for resuming trade with the Islamic Republic would not be operationalized unless the Iranians adopted the anti-money laundering standards of the Financial Action Task Force.

Even assuming that last Saturday’s attacks can be credited to the Houthi, they shine additional light on the reasons why Iran is unlikely to embrace the FATF. While the Iranian parliament passed legislation that would have brought the country into partial compliance, even these measures have been obstructed by more powerful hardline authorities like the Guardian Council. In so doing, they have clearly expressed their concern that such compliance would interfere with the regime’s ability to finance and support the Lebanese Shiite terrorist group Hezbollah. And these concerns can presumably be extended to other foreign entities that are essential to Tehran’s interventionist foreign policy, like the Houthi.

If the smuggling of ever-larger supplies of weapons to those groups demonstrates an unwillingness to compromise with Western adversaries, that message is conveyed even more strongly by direct participation in hostilities alongside the Houthi. By extension, the latter move might be expected to move European policymakers even further toward alignment with the maximum pressure strategy. But in keeping with longstanding wariness about deviating from the status quo, those policymakers are generally displaying caution in the wake of the initial accusations against Iran.

In remarks to the United Nations Security Council, British Ambassador Karen Pierce said, “We’re still assessing what happened and who’s responsible for the attacks. Once this has been established we will discuss with our partners how to proceed in a responsible manner.”

White House: No Doubts, No Negotiations

But even though President Trump acknowledged that nothing has been fully verified, further statements from his administration have evoked little doubt about Iran’s responsibility. The president also sought to put his suspicions in the context of a broader pattern of Iranian behavior. Referring to an American drone that was shot down by the Revolutionary Guard Corps in June, Trump tweeted that the Iranians claimed “that it was in their ‘airspace’ when, in fact, it was nowhere close. They stuck strongly to that story knowing that it was a very big lie. Now they say that they had nothing to do with the attack on Saudi Arabia. We’ll see?”

When we do see about this, we will no doubt also see what the US intends to do about it. The administration’s decisions may depend in some measure on various allies’ responses to calls for a coalition by the likes of Perry and Pompeo. But independent of demands for multilateralism, many supporters of the current US strategy for Iran are looking toward new avenues for applying maximum pressure.

As part of a thread of tweets responding to Saturday’s attacks, Senator Lindsey Graham said, “Iran will not stop their misbehavior until the consequences become more real, like attacking their refineries, which will break the regime’s back.” Indeed, the White House has indicated that a military response is on the table, though it bears mentioning that Trump called off a retaliatory strike following the aforementioned drone shoot-down, stating that the potential death toll would have been disproportionate. According to Saudi Arabia, no one was killed in Saturday’s strikes.

On Monday, Fox News national security analyst General Jack Keane stopped short of advocating for a military response but did emphasize that the option should remain, that the US “holds all the cards,” and that Trump should avoid giving Tehran any new opportunities to negotiate following the regime’s latest effort to force concessions from the US and its allies.

“The Iranians are gonna exhaust their playbook, I believe, before they come to the negotiating table,” Keane said, then added that, “based on their actions, we can isolate them politically and economically and squeeze them even further.” Keane was not specific about the outcome he envisioned for this approach, but the natural motivation for avoiding negotiations over the short term is to impose preconditions at a later date.

In the immediate aftermath of Saturday’s attacks, Secretary Pompeo seemed to dismiss talks with Iranian officials as having no real value. “Tehran is behind nearly 100 attacks on Saudi Arabia while [President] Rouhani and [Foreign Minister] Zarif pretend to engage in diplomacy,” he said. Yet both those Iranian figures have repeatedly stated that Tehran will not negotiate with Washington until after US sanctions are lifted. Attacks on Saudi Arabia bring new urgency to the question of what the Iranian regime will do in an effort to secure this precondition.