WASHINGTON - Iran is providing a broad array of assistance to Syrian President Bashar Assad to help him suppress anti-government protests, from high-tech surveillance technology to guns and ammunition, US and European security officials say.Tehran's technical assistance to Assad's security forces includes electronic surveillance systems, technology designed to disrupt efforts by protesters to communicate via social media, and Iranian-made drone aircraft for overhead surveillance, the officials said. They discussed intelligence matters on condition of anonymity.Iran not a game changerHowever, the US and European officials said the Syrian government's survival is not totally dependent on continuing help from Tehran.US and allied official broadly agree that Assad's control remains solid. His opponents are hopelessly disorganized, the officials said, which may make it possible for the Syrian president and his entourage to hold onto power for years."At current levels Iranian aid is important but not really a game changer in the overall conflict," a US official noted.Iran has for decades been a patron to Syria, which has helped funnel aid and weapons to the Iranian-backed Shi'ite Muslim militia Hezbollah in Lebanon.During the protests that followed Iran's disputed 2009 presidential election - the biggest mass protests since the Islamic Republic's founding in 1979 - Iranian authorities disrupted social media, such as Facebook and Twitter, as well as cell phone networks.Iran's internal crackdown reportedly has escalated since then.A European official said that the Iranians were providing Syrian security agencies with hardware and software that would help them disrupt efforts to organize protests inside Syria and efforts by anti-government elements to spread their message to supporters outside the country.Officials said that Syria had also obtained some surveillance technology from European suppliers.As protests against Assad's rule grew last year, the United States first raised the possibility that Iranian authorities were helping their Syrian counterparts suppress dissent.Last June the US Treasury Department announced economic sanctions against two of Iran's most senior police officials for allegedly helping Assad's government crush protests.The Treasury imposed US economic sanctions on Ismail Ahmadi Moghadam and Ahmad-Reza Radan, chief and deputy chief of Iran's national police force, because their agency had "provided support to the Syrian General Intelligence Directorate and dispatched personnel to Damascus in April to assist the Syrian government in suppressing the Syrian people."The Treasury alleged that Radan had traveled to Damascus to meet with Syrian security agencies, to whom he allegedly provided "expertise to aid in the Syrian government crackdown on the Syrian people."The drone debateUS officials said Iranian efforts to bolster Syria's surveillance capabilities have been supplemented by deliveries to Syria of Iranian-made unarmed surveillance drone aircraft.Earlier this month a specialized website, The Aviationist, reported that a drone flying over the city of Homs, the site of recent violent clashes between government and opposition forces, had been identified as a "Pahpad" drone, which the website said meant "remotely piloted aircraft" in Farsi.In February another specialized website, Open Source GEOINT, published freeze-frame images from what purported to be an amateur cameraman's video of a suspected drone flying over a Damascus suburb.The website noted that some news reports had suggested that the United States was flying intelligence drones over Syria but that the drone in the pictures did not appear to be a US model.The website cited speculation that the drone might be of Iranian origin. Israel's Ynet website reported this month that Syria's defense industry produces drones that are technologically identical to Iranian-produced models and speculated that these domestically produced models were what Syrian security forces had deployed.However, a US official said that some of Syria's drones had come directly from Iran.Last weekend the Iranian news agency Fars announced that Iranian experts had produced what it called a "new type of drone" known as the Shaparak, or "Butterfly," which it said was "capable of carrying out military and border patrol missions."Iran has also provided lethal materiel that can be used for riot control, they said."Over the past year, Iran has provided security assistance to Damascus to help shore up Assad. Tehran during the last couple of months has been aiding the Syrian regime with lethal assistance - including rifles, ammunition, and other military equipment - to help it put down the opposition," a US official said."Iran has provided Damascus (with) monitoring tools to help the regime suppress the opposition. It has also shared techniques on Internet surveillance and disruption," the official continued.He added that Iran had also provided Assad's government with "unarmed drones that Damascus is using along with its own technology to monitor opposition forces."Iranian security officials have also traveled to Damascus to advise Assad's entourage how to counter dissent, the official said. Some Iranian officials have stayed on in Syria to advise Assad's forces, he added.Iran's multi-pronged security aid to Syria appears to have helped Assad's government in its increasingly violent campaign to hold on to power in the face of a year-long protest movement. The United Nations estimates 8,000 civilians have died in the conflict.