<br/> When the <em>USS Vincennes</em> mistakenly blew an Iran Air plane out of the sky more than three decades ago in 1988, Iran showed foreign journalists dozens of twisted and dismembered corpses of the passengers. The Islamic Revolutionary Guard Corps gave international media no such access after bringing down a Ukrainian airliner carrying Iranians and other nationalities last week with at least one missile it later said was fired in error. Having shown public contrition, the IRGC is in damage-control mode but the costs might amount to more than prestige for the armed bedrock of the clerical system in Tehran. Tasked with defending and spreading the 1979 revolution that created the Islamic Republic, and operating “in parallel with conventional forces”, the IRGC is Iran’s “political army”, said Guido Steinberg of the German Institute for International and Security Affairs in Berlin. The downing of the Ukrainian jet prompted rare public calls within the regime to hold military officials accountable. There was little direct criticism of the IRGC. But street protests that broke out in Tehran after the admission of guilt on Saturday were reported by the pro-regime Fars News Agency, indicating displeasure from within. The protests came a month after the authorities reportedly killed 1,500 people in their efforts to crush mass protests over fuel price hikes. Iran has severe curbs on independent media. But it appeared from Fars news agency reporting and social media that crowds have been demanding the resignation of supreme leader Ayatollah Ali Khamenei and chanting "death to liars". Some of the demonstrators even tore pictures of Qassem Suleimani, a top IRGC commander killed by a US drone strike in Iraq on January 3. His killing prompted what many considered to be a warning missile attack on Iraqi military bases hosting US personnel. The attack, diplomats in the region and observers said, was significantly designed to assuage the regime’s core constituency. Among them are millions in the IRGC’s regular forces, and its paramilitary unit, the Basij, and ordinary Iranians still supportive of the 1979 revolution. They have constituted a major, and significantly armed, counterweight to the protest movements in Iran in the past several years. The IRGC had mobilised masses of Iranians for several funeral processions for Suleimani and an Iraqi militia leader also killed in the US strike. But the public displays of grief and defiance against the US were marred by death of 56 people in a stampede near Suleimani’s burial site in Kerman, and undermined by the resumption of the protest movement in Iraq. Amid pressures at home and abroad, some supporters of Iran in the West and other observers are questioning the trajectory of the clerical leadership towards more repression in connection with its reliance on the IRGC. Last month, foreign policy author Daniel Brumberg of Georgetown University asked whether Iran was “on the edge of a precipice”. The “number one priority” of Mr Khamenei is reasserting control, Mr Brumberg wrote in an article on LobeLog, a US blog focused on Iran. “This requires a close alliance with the IRGC, even if such an entente could further isolate the supreme leader and the office he embodies,” Mr Brumberg said. Mr Brumberg suggested that Mr Khamenei may in some ways be dancing with the devil, but inside and outside Iran the IRGC has been “pushing back with its own pressure campaign”. Ronald Reagan called the downing of Iran Air Flight 655, which killed 290 people, a tragedy. Iran termed it a massacre and the IRGC and the political establishment made it a constant rallying cry against what they regard as the victimisation of Iran for decades afterward. It has been a tool for unity that may have lost its effectiveness after Ukraine International Airlines Flight 752 was brought down, killing all 176 aboard.