BAGHDAD (Reuters) - Thousands of Shi'ite Muslims from Iraq and beyond will take up arms against Sunni al Qaeda "savages" in Syria if fellow Shi'ites or their shrines come under attack again, a powerful minister in Iraq's Shi'ite-led government said.
It would be impossible to "sit idle while the Shi'ites are being attacked", while the United States and Western allies arm and finance the mainly Sunni rebels fighting against Syria's government, Hadi al-Amiri told Reuters in an interview.
Amiri, Iraq's transport minister, is head of the Badr Organisation, a political movement which arose from a heavily-armed Iran-trained militia and many of whose members are now part of Iraq's security forces.
After two years of fighting that has left 93,000 dead, the Syrian civil war is increasingly being fought along sectarian lines, with mainly Sunni rebels fighting to overthrow President Bashar al-Assad, whose Alawite sect derives from Shi'ite Islam.
The conflict is splintering the Middle East along a divide between the two main denominations of Islam, becoming a battlefield in a proxy war between Assad's main regional ally, Shi'ite Iran, and his Sunni enemies in Turkey and the Gulf Arab states.
With Russia and Iran arming Assad's forces, and Lebanon's Hezbollah Shi'ite militia joining the war on Assad's behalf, Western powers have agreed in the last week to increase aid to the mainly Sunni rebels.
Amiri said Shi'ites had been galvanised by the killing of around 60 members of their sect at the hands of Sunni insurgents in Syria's eastern province of Deir al-Zor earlier this month.
"If another attack against Shi'ites takes place similar to Deir al-Zor, or against the shrine of Sayyeda Zeinab, not only a handful of men, but thousands of Shi'ite men will go to fight alongside the regime and against al Qaeda and whoever backs al Qaeda," Amiri said.
"After Deir al-Zor, thousands of Shi'ite youths from Iraq and all over the world will head to fight in Syria. If 300 Lebanese Hezbollah fighters changed the equation in Syria, Iraqi young men will go to Syria to change it a hundred times over," Amiri said, referring to Hezbollah forces whose intervention enabled Assad loyalists retake the town of Qusair this month.
Traditional Shi'ites revere the Prophet Mohammad's son-in-law Ali and 11 of his descendants as imams, maintaining shrines to them across the Middle East. The Sayyeda Zeinab shrine south of Damascus, devoted to Ali's daughter, now has hundreds of foreign Shi'ite volunteers guarding it from rebel attacks.
The bombing of a Shi'ite shrine housing the tombs of two imams in the Iraqi city of Samarra in 2006 was the trigger for the worst sectarian carnage between Sunnis and Shi'ites that engulfed Iraq in the middle of the past decade.
Shi'ite leaders such as Hezbollah's Hassan Nasrallah in Lebanon have issued warnings against any repeat of that attack against shrines in Syria.
Shi'ites are a minority in most of the Middle East but form the majority in both Iran and Iraq.
Amiri's Badr Brigades militiamen fought on Iran's side in the 1980-88 war against Iraq Sunni dictator Saddam Hussein's government. The militia came to dominate much of southern Iraq after the U.S.-led invasion in 2003 toppled Saddam, and during the sectarian fighting that followed.
After the last general elections in 2010, Amiri shifted his loyalties to Prime Minister Nuri al-Maliki, leader of the rival Shi'ite Daawa Party.
While it is unclear to what extent he is reflecting the views of the Maliki government, Amiri pulls no punches on Syria.
"Do you want us to sit idle while the Shi'ites are being attacked, while the Americans and the rest are helping them with weapons and money? What do you expect?"
He said young Iraqi volunteers are going to Syria via Beirut or flying from Baghdad to Damascus.
Asked whether the Iraqi government sponsors Shi'ite fighters across the border, Amiri compared the flow of Shi'ite fighters from Iraq to the influx of Sunni militants from Tunisia, Libya, Egypt and other Arab countries.
"As long as those governments say they are not aware (of fighters going to Syria) we also in the Iraqi government are unaware," he said, adding the official line that Iraqi fighters are not state-sponsored and they go to "protect their Shi'ite shrines".
Streams of Sunni Islamist fighters have already converged to wage holy war in Syria, where the al Qaeda-linked Nusra Front is sidelining more moderate groups that do not share its goal of establishing a Sunni Islamic Caliphate in the country.
Nusra has announced a merger with Iraq's branch of al Qaeda, which spent the last decade fighting U.S. troops and the Shi'ite-led Iraqi authorities, and which Baghdad blames for bomb attacks that still kill civilians and police.
Last month 1,000 people were killed in bomb attacks in Iraq, the deadliest month since the sectarian slaughter of 2006-07.
Amiri ridiculed the idea that Western powers could ensure weapons only reached the hands of moderate rebel groups, describing al Qaeda and its affiliates as "savages".
"The powerful ones in the Syrian arena are the Nusra Front and they would take the arms from the moderates by force," he said. "We believe that any arms that reach the Nusra Front will be directed against the Iraqis."
Amiri, like other leaders in Baghdad and Tehran, fears Assad's demise would make way for a hostile Sunni Islamist government in Syria that would weaken Shi'ite influence in the Middle East and eventually turn its sights on Iraq and Iran.
Re-invigorated by the Syrian conflict, al Qaeda's Iraqi affiliate is gaining strength and recruits from Sunnis who resent Shi'ite domination since the fall of Saddam.
"I fought and carried arms against Saddam for over 20 years… I swear by God that if I had to choose between Saddam Hussein and al Qaeda I would fight alongside Saddam and against al Qaeda. There is no one worse than al Qaeda," Amiri said.
Reporting by Samia Nakhoul and Suadad al-Salhi; Writing by Samia Nakhoul; Editing by Peter Graff