Last year was not altogether kind to the Kingdom of Saudi Arabia. Financial hardships amid an era of cheap oil, Islamic State (IS) attacks on Saudi Arabian soil, a costly quagmire in Yemen and setbacks in Syria have all weakened the kingdom’s position in the region. Despite these challenges, Saudi Arabia has managed to establish a network of Sunni states within the framework of the Islamic Military Alliance to Fight Terrorism (IMAFT). Although the US-backed anti-terror coalition’s purpose is to crush IS, al-Qaeda and other extremists, the notable absence of Iran and Iraq from IMAFT illustrates the members’ geosectarian alignment with Riyadh’s anti-Iran posturing.

Last month, the kingdom scored another victory by bringing in a new member: Oman. For the sultanate, which has traditionally distanced itself from Riyadh’s efforts to isolate Tehran, joining IMAFT raises important questions about Muscat’s foreign policy agenda as Arab Gulf-Iranian tensions escalate. Saudi voices were quick to hail Oman’s decision to become the Saudi-led alliance’s 41st member as a sign of strong Gulf Cooperation Council (GCC) strength and "a new chapter in regional and Muslim unity."

As neighbors and fellow GCC states, Oman and Saudi Arabia have long maintained a close alliance, yet Muscat’s close ties with Iran have created friction in Omani-Saudi relations. By hosting secret talks between American and Iranian officials in Muscat, which led to the historic 2015 Iranian nuclear deal, Omani officials unnerved their Saudi counterparts. More recently, members of the Saudi government have accused Oman, which has thus far maintained neutrality in the Yemen civil war, of permitting weapons smuggling across the Oman-Yemen border into the hands of Houthi fighters — a claim denied by officials in Muscat.

During his tour of GCC states last month, King Salman bin Abdul-Aziz Al Saud's notable exclusion of Oman signaled Riyadh’s disapproval of Muscat’s close ties to Tehran, even if Saudi officials never publicly aired their frustrations with the sultanate. According to a former high-ranking GCC official, some in the council view Oman’s neutrality as "negative neutrality" given that the Saudis and others seek to establish a unified Arab Gulf front against Iran and its regional allies from Lebanon to Yemen.