DUBAI/RIYADH — Gulf Arab states have long feared a sanctions-free Iran and as a nuclear agreement edges closer they have become more aggressive in preparing for a resurgence of their main regional foe. The biggest concern is what they see as Shiite Iran's regional expansionism, manifest in its backing for Syria's President Bashar Al-Assad, Lebanon's Hezbollah, Iraq's Shiite militias and Yemen's Houthi group. From the airstrikes in Yemen to backing for Syrian rebels, crackdowns on dissent and more forceful diplomacy, the actions of the mostly Sunni Muslim Gulf states in recent months has been driven by a sense that Iran is on the cusp of a comeback. They are also concerned that US President Barack Obama's push for a nuclear deal in return for sanctions relief shows their strongest ally may no longer help restrain Iran. "The deal is inevitable is their calculation. It could be delayed a week or two, or a month. But everybody in the region has prepared himself for the reality that the deal is a done thing," said Mustafa Alani, a security analyst. The six Gulf Cooperation Council (GCC) members, Saudi Arabia, Kuwait, Bahrain, Qatar, the United Arab Emirates and Oman, often disagree on regional strategy, but except for Muscat, they all share misgivings about Iran. For Saudi Arabia in particular, revolutionary Shiite Iran represents an overriding threat in a hostile region. Bahrain's announcement last week that it had discovered an explosives plot it said was planned by Iran's Revolutionary Guards was only the latest example of what Gulf states see as Tehran's ongoing efforts to undermine their security. Alternative alliances Six world powers — Britain, France, Germany, China, Russia and the United States — and Iran will recommence talks this week aimed at reaching a final agreement that swaps increased transparency for sanctions relief by June 30 after reaching a framework deal in April. Riyadh and its dynastic neighbors are also worried about the implications for relations with Washington, their main military guarantor with its aircraft carrier group in the Gulf, naval base in Bahrain and air base in Qatar. "Obama is going to be remembered as the US president who restored relations with Iran. But he may also be remembered as the US president who lost his traditional allies in the region," said Sami Al-Faraj, a Kuwaiti security adviser to the GCC. Gulf states have increasingly voiced the idea of building alternative alliances to replace a diminished American role in the region, and have showcased that ambition with the coalition in Yemen and renewed cooperation with Turkey in Syria. "We have been looking for other options, whether it is Russia, France or regional powers like Turkey and Pakistan, to enable us to regain a balance of power," said Faraj. — Reuters