The pending development of MESA is indicative of recent trends that have emerged in response to the Iranian regime’s destabilizing actions in the region. The proliferation of Iran-backed militant groups in Syria, Iraq, Yemen, and elsewhere has generated a great deal of concern about a growing threat to the interests of the Gulf Arab states as well as to Israel and their Western allies. But the Egyptian withdrawal is indicative of the uncertainty with which some nations are viewing the collective response, especially those nations that are in some sense torn between partnerships with the US and Iran.

The Egyptian government acknowledged its second thoughts ahead of a meeting of the prospective member states, which was scheduled for Sunday. It was not immediately clear whether any particular event or statement had precipitated the withdrawal decision, and an anonymous Arab source told Reuters that multiple rationales were given, including doubts about the seriousness and specificity of the proposal, and concerns that it would only exacerbate existing tensions with the Islamic Republic.

This latter concern was likely elevated by the announcement, earlier the same week, that the Trump administration would be designating and sanctioning the Iranian Revolutionary Guard Corps as a foreign terrorist organization. This prompted Tehran to make a similar declaration about the US military, and it spurred vigorous debate in the international press about the prospective impact of such measures on relations among the two countries and their respective allies.

There is little question about the potential for the IRGC terror designation to increase tensions, but as one policy analyst explained in an interview with CNBC, the White House truly believes that a strategy of “maximum pressure” will bring Iranian officials back to the negotiating table and convince them to, in the words of Secretary of State Mike Pompeo, “behave like a normal country.”

From the explanation of Egypt’s reasoning behind the pullout from MESA, it is not clear whether its government lacks confidence in the strategy itself or merely has questions about whether it is being effectively implemented. If the latter, then Cairo’s doubts are shared even by some of President Trump’s allies inside Washington, as evidenced by a report published in Bloomberg on Thursday.

That report highlights an effort by several Republican senators to accelerate the “maximum pressure” campaign even in the wake of the IRGC terror designation. Specifically, those lawmakers urged the cancellation of waivers associated with the 2015 Iran nuclear deal, from which the US withdrew last year. An April 9 letter to the president urges him to “finally end all US implementation” of that deal by disallowing allied countries from continuing to facilitate Iran’s civilian nuclear program, which many suspect to have functioned as a cover for Tehran’s pursuit of nuclear weapons.

This particular call to action by Iran hawks goes hand-in-hand with demands for an end to waivers on purchasing of Iran’s oil exports, which were granted to eight countries when the sanctions came back into effect last November. The White House is reportedly considering the possibility of allowing all of those waivers to expire without renewal next month, and Brian Hook, the State Department’s special envoy for Iran policy, has boasted that three of the eight recipients have already halted all imports of Iranian oil.

Market conditions could make it difficult to withhold all waivers without sparking a surge in global oil prices, although several of the MESA member states could help to avoid this situation by raising their own petroleum output in advance. President Trump has made a number of public statements urging them to do just this, but Saudi Arabia and other members of the oil exporting countries are currently holding firm to an agreement that sets specific limits on production.

From the perspective of Egyptian policymakers or anyone else who is uncertain about the seriousness of MESA’s plan to contain Iran, this sort of reluctance may not be confidence-inspiring. But if the slow progress toward “maximum pressure” is part of Egypt’s reasoning, then its withdrawal from the alliance could motivate the Saudis and their partners to reconsider Trump’s recommendation.

Notably, sources close to MESA discussions indicated that Egypt’s decision did not appear to be final and could still be revoked. Furthermore, the other states appear uniformly committed to preserving and formalizing the full alliance, and may be willing to take new steps to see that this happens. “We all want them back,” one of those sources said of Egypt’s uncertain membership.