In an era where Arab regimes seem to be in constant battle, Egypt and Saudi Arabia—the cornerstones of a moderate Arab pro-American camp and counterweights to Iran—have not only continued their old alliance but have strengthened it, too. Following a U.S. retreat from its historically intense role in the Middle East, Egypt and Saudi Arabia are now finding themselves, for the first time in years, having to form policies without U.S. input. They must now decide how to face the possible implications of the Iran nuclear deal, the ongoing crises in Syria and Yemen, and the growing threat from the self-proclaimed Islamic State (also known as ISIS).

Indeed, at the beginning of the year, Cairo and Riyadh announced that they were seeking to establish a joint military force, with Saudi Arabia providing most of the funding and Egypt providing most of the fighters. Then, in August, they signed the “Cairo Declaration,” which encompasses a range of areas of cooperation over common regional challenges. In the last couple of months, the two sides have held a number of high-level talks, including the meetings of their foreign ministers on October 25 in Cairo and the meeting of Egyptian President Abdel Fattah el-Sisi and Saudi King Salman on November 11 in Riyadh, during which they approved the establishment of a coordination council to implement the "Cairo Declaration."

However, as much as the regional unrest might motivate Riyadh and Cairo to cooperate, these conflicts have given them reason to fight, first and foremost over how to deal with Syria and Yemen and also on how to handle Islamist political groups in the region, such as the Muslim Brotherhood.

Saudi King Salman bin Abdulaziz walks with Egypt's President Abdel Fattah al-Sisi in Riyadh, November 10, 2015. Faisal Al Nasser / Reuters

RECENT BICKERINGS

Cairo and Riyadh have many things in common. They both frown upon Iran’s increasing interference in what they see as “Arab internal affairs”—namely, Iran’s support for Shiite groups in Arab countries such as Bahrain, Lebanon, Syria, and Yemen—and are irked at the United States’ apparent pullback from the region. However, Cairo is less dependent than Saudi Arabia on the United States for its regional security and, although worried about Iran, is not as hostile toward it.

The rise of ISIS, however, has given them yet another shared enemy and has forced both to reprioritize their struggles. Here, Saudi Arabia and Egypt diverge: the main threat to Saudi Arabia’s national security continues to be Iran, but Egypt sees the chaos in Libya and the Sinai Peninsula as the source of its greatest threats.

Additionally, in recent months, Saudi Arabia and Egypt have bickered over what stance to take on Syria. Cairo, it seems, does not strongly oppose the continued rule of Syrian President Bashar al-Assad because it sees Assad as a lesser evil than the Islamists, whose victory could fuel the ambitions of similar groups in Cairo. Saudi Arabia wants to remove Assad because of his close alliance with Iran. Riyadh has thus been calling for the immediate removal of Assad as a precondition for any political arrangement in Syria. Meanwhile, Egypt has given minimal support to armed opposition groups since the start of the civil war. It supported several nonviolent Syrian elements, such as the National Coordination Committee for the Forces of Democratic Change, that were ready for dialogue and reconciliation with the regime. Publicly, however, both sides stressed their common interest in a solution to the Syrian crisis by the Syrian people and played down their disagreements, sweeping them under the rug.

Riyadh and Cairo are also divided over the Russian intervention in Syria, which has targeted opposition groups. Saudi Arabia denounced the move, seeing it as an attempt by Moscow to preserve the Assad regime. Cairo, on the other hand, gave Russia its blessing, characterizing the move as part of a war against terror in Syria. Thumbing his nose at the rebels that Gulf states support, Sisi warned the Gulf states in a speech in Bahrain on November 1 against backing “terrorist groups” that are attempting to broaden their influence and threatening to undermine the Arab states’ social and ethnic fabric.

It is now incumbent upon Riyadh and Cairo to try to bridge the divides that plague them—or, alternatively, to accept the fact that they will not reach full agreement on all the issues and that both of them are allowed a degree of leeway, particularly on the issue of Syria.

POLITICAL ISLAM

The bickering over Syria is part of a larger disagreement on the role of political Islam, especially the Muslim Brotherhood. Egypt does not distinguish between the jihadist groups in the Sinai that are affiliated with ISIS and the Muslim Brotherhood, which says it is committed to nonviolence (even though there have been occasional clashes).

Riyadh has a slightly different take. It is wary of radical Islamists, but with an increasingly powerful Iran, Saudi Arabia has swallowed the bitter pill that is the Muslim Brotherhood. In doing so, it has been able to form a tighter anti-Iranian front that includes Turkey and Qatar, which are essentially patrons of the Brotherhood. (Several members of the Muslim Brotherhood fled to Turkey after the fall of former Egyptian President Mohamed Morsi and set up an outpost there.)

Friendly ties with Islamist groups also serve Riyadh’s goals in Yemen, where it is essentially fighting a proxy war with Iran. It is seeking to bring down the Iran-backed Shiite-Houthi rebels, who took over the capital in September 2014. In its attempt to strengthen its influence in the war-torn country, Saudi Arabia is growing closer, to Egypt’s chagrin, to the Islamist Islah Party, which is affiliated with the Muslim Brotherhood.

Unlike Saudi Arabia, Egypt does not ascribe too much importance to the conflict in Yemen and does not view it as a threat to its national security. Cairo is currently preoccupied with domestic issues, such as Islamist militants in the Sinai Peninsula; in July, a clash between these militants and the Egyptian army left 117 dead. Moreover, there are many in Egypt who remember the traumatic failed intervention in Yemen by former President Gamal Abdel Nasser in 1963. They do not want to get stuck, yet again, in “Yemeni mud.” As a result, Egypt’s military participation in the Saudi-led coalition in Yemen is largely symbolic and limited principally to naval operations.

CONGRUENCY AND CONFLICT

The benefits to Egypt and Saudi Arabia of a strengthened partnership still outweigh its downsides. Egypt, which has trouble balancing its budgets, is in need of continued economic support from Saudi Arabia, which alongside its rich neighbors (the United Arab Emirates and Kuwait) has pledged to give more than $20 billion to the Egyptian government since the 2013 coup. To the Saudis, the “investment” has already yielded some results—namely, Egypt’s support for its operation in Yemen, even if it is mostly political. Of course, Egypt is not prepared to forfeit its own interests for those of Saudi Arabia but, rather, is carefully establishing mechanisms of cooperation and coordination in an attempt to contain disputes and prevent them from rising to the surface.

A recent example of their attempt to show a united front and contain disagreements, at least publicly, was during the latest visit by Saudi Foreign Minister Adel al-Jubeir to Cairo in late October 2015. In the course of the hours-long visit, he affirmed the “congruent stances” of Egypt and Saudi Arabia on Syria and Yemen, while also saying that they “[hadn’t] reached an agreement yet” and that more discussion on the issues was needed.

It is now incumbent upon Riyadh and Cairo to try to bridge the divides that plague them—or, alternatively, to accept the fact that they will not reach full agreement on all the issues and that both of them are allowed a degree of leeway, particularly on the issue of Syria. Without Saudi economic aid, the Egyptian regime will find it almost impossible to keep up with its internal reforms and stabilize its rule. Saudi Arabia, on the other hand, cannot afford to lose its closest ally given the current regional turmoil. If the two do not bridge their differences, it would be destructive not only for them but for the fragile balances of power in the region.