Arab Gulf states on Monday delayed plans to deepen political cooperation between them, reflecting unease on the part of smaller nations in the six member Gulf Cooperation Council about handing more power to Saudi Arabia.

Saudi Arabia and its neighboring Arab Gulf kingdom of Bahrain had expected to announce plans for increased economic and security cooperation in a move that Riyadh hoped would have spurred political integration all of the Sunni monarchies on the peninsula.

With rival Iran pursuing an uranium enrichment programs which neighboring Arab countries and the West suspect is designed to develop nuclear weapons and sectarian tensions between Sunni and Shia Muslims rising across the Middle East, forming a union “has become urgent,” Bahrain’s prime minister Khalifa bin Salman said on Sunday. Several of his allies disagreed.

Qatar enjoys the freedom to pursue a foreign policy that is more independent of the United States than Saudi Arabia’s and like the United Arab Emirates, it fears Saudi domination.

The emirates pulled out of a planned monetary union among the GCC states in 2009 after Saudi Arabia was voted as the host of a common central bank. Unable to agree to the creation of a joint missile shield, they also purchased their own defense system late last year.

Kuwait would have difficulty joining “with countries whose prisons are full of thousands who are guilty of speaking their minds,” the speaker of the emirate’s parliament said in February of last year in a reference to the Saudi kingdom. Persecution of the Shia minority sect has only increased in Saudi Arabia with the onset of the “Arab Spring” which forced its longtime Egyptian president and ally Hosni Mubarak out of office last year.

In December, Saudi king Abdullah made an impassioned appeal for fellow Sunni rulers to join forces. “You all know that we are targeted in our safety and security,” he told his neighbors at the time.

Saudi Arabia’s foreign minister Saud bin Faisal Al Saud added last month, “The threats of all kinds require the hard works of the GCC countries to shift from a current formula of cooperation to a union formula acceptable to the six countries.” He didn’t specify what threats the Gulf states face but their leaders suspect that Iran is conniving with Shia opposition in their countries to destabilize the Sunni regimes.

Because they have common interest, the delay came as a surprise. The meeting of Arab Gulf leaders on Monday was expected to endorse what has happened on the ground — an effective union between Bahrain and Saudi Arabia. The island nation is highly dependent on its neighbor for financial assistance, trade and military protection. Saudi troops that were deployed to Bahrain in May to quell a largely Shia uprising against the ruling Al Kalifa family have yet to depart.