When Iranian rockets and drones hit the US 5th Fleet in Manama, videos posted on social media showed some Bahrainis celebrating the strikes. The videos revealed the deep-seated anger felt by many at the killing of Ayatollah Ali Khamenei, Iran’s Supreme Leader, and a spiritual figure for Shia Muslims around the world. For the Bahraini authorities, the videos once again raised suspicion about the loyalties of Shia inhabitants of the country, highlighting the multiple security calculations emerging from the conflict.

One hundred days into the war, and a diplomatic resolution appears within reach, albeit merely a Memorandum of Understanding at this point. Even if there is a final agreement, the memory of the past 100 days will linger for years to come. Finding a way to address the suspicion and animosity is of paramount importance.

Amongst the many different issues raised by the conflict, the question of regional security is perhaps foremost in the minds of Gulf leaders. The conflict has highlighted the vulnerabilities that come with relying on the US for security. Moreover, as several officials have stressed, Arab Gulf states cannot change their geography; they have to find a way of living alongside the Islamic Republic and, in addition, create an environment that is conducive to the security of all parties.

This conclusion had previously been reached by Saudi Arabia following the attacks on Abqaiq and Khurais oil refineries in 2019. Furious Saudi officials had expected a forceful response from the US, but this was not forthcoming. Instead, in a marked policy shift, the Kingdom embarked on a long and arduous process of resetting relations with Iran, a state with which the Saudis had severed diplomatic relations in 2016. This process took a huge amount of effort and the work of countless intermediaries who undertook track II diplomatic efforts, highlighting the depth of animosity between the two states. Ultimately, diplomatic efforts were successful, seen through the normalisation agreement signed in 2023 in Beijing. Yet recent developments appear to have derailed this progress.

The volume of strikes conducted by Iran on its Gulf neighbours makes shared security an increasingly challenging outcome to achieve. Though Tehran was initially quick to stress that strikes were on US targets, not against their Arab and Muslim brothers - statements that were swiftly rejected by Gulf leaders - as the war progressed, strikes also hit non-US targets within the Gulf states.

Across the past 4 decades, geopolitical crises have resonated within states as well as between them. A closer look at history in this time highlights this. Suspicion at the region’s Shia inhabitants has long plagued politics across the Arab Gulf states. Since the establishment of the Islamic Republic of Iran and the articulation of an expansionist foreign policy in support of the “downtrodden” of the Muslim world, the region’s Shia population has been viewed with suspicion and trepidation by many of their Sunni counterparts.

Iranian involvement in the establishment of Hezbollah, the Islamic Front for the Liberation of Bahrain, collaboration with Hezbollah al Hijaz, and other Shia groups fostered suspicion towards both Tehran and their coreligionists across the Middle East. Statements from Ruhollah Khomeini, the theological architect of the Islamic Republic, and other Iranian officials about exporting the revolution exacerbated many of these concerns.

Following the US lead invasion of Iraq in 2003, narratives of perfidious Iranian engagement across the Middle East reverberated, perhaps best captured in King Abdullah of Jordan‘s remarks about a Shi’a Crescent that spread from Iran all the way across to the Mediterranean Sea. This again hinted at the divided loyalties among local Shi’a populations and Iran's growing capacity to manipulate those divisions. What followed was the emergence of a climate of distrust and violence, exacerbated by the sectarian conflict that consumed Iraq following the fall of Saddam Hussein. Fearing the growing influence of Iran, Bahrain’s rulers sought to cultivate closer relations with Israel back in 2007, some 13 years before the signing of the Abraham Accords.

When the Arab Uprisings broke out in 2011 the legacy and memory of Iranian actions during the 1980s shaped the responses of many in Bahrain for example the ruling Al Khalifa family framed protesters as nefarious Iranian fifth colonists With some evoking memories of the 1980s to justify these actions. Others suggested that Iran had been smuggling weapons into Bahrain while similar developments were felt in Kuwait with terrorit plots allegedly thwarted by the state.

As history has shown, trust is difficult to build but easy to shatter. But geography is inescapable. Qatar shares a gas field with Iran, there is a large Iranian population in the UAE, and the Islamic Republic has cultivated positive relations with Oman. While the signing of the Saudi-Iran normalisation agreement shows that suspicion can be overcome, the sheer volume of Iranian attacks on Gulf states has provoked deep anger and concern. Add possible spoilers into the mix and the situation remains volatile, even if a final agreement can be reached.

Much of the goodwill generated between the Saudis and Iranians from March 2023 to February 2026 has dissipated. Few will trust Iran moving forward, especially if, as some suggest, the Islamic Republic is emboldened by the outcome of the war (which is looking increasingly likely). Whether trust can be restored between states in the Gulf, but also between different sectarian communities within states, remains to be seen.

Simon Mabon is Professor of International Politics at Lancaster University and the author of Schism: The Story of Sectarianism in the Modern Middle East (Yale University Press, 2026).