News that the Royal Canadian Mounted Police have arrested two Muslim men on charges of plotting to blow up a train with “support from Al Qaeda elements located in Iran” has been met with widespread and ill-deserved incredulity. Typical is this BBC report, which claims: “It is difficult to believe that there is an operational alliance between Iran, a hard-line Shia Muslim state, and al-Qaeda, an extremist Sunni Muslim outfit.”

Actually it’s not that hard to believe at all. There is copious evidence of the links between Iran and al-Qaeda, as noted by Bill Roggio in the Long War Journal: “In recent years, the US government has added several Iran-based al Qaeda leaders and operatives to its list of specially designated global terrorists, and even noted a ‘secret deal’ between the Iranian government and al Qaeda.”

Full details are available in Roggio’s invaluable post, which goes on to note that Iran also supports another Sunni extremist group: the Taliban: “Treasury has also noted Iran’s support for the Taliban, as in August 2010 it added two top Iranian Qods Force commanders to its list of specially designated global terrorists for directly providing support for the Taliban in neighboring Afghanistan.”

Roggio’s post is well worth reading for anyone who can’t imagine terrorists cooperating across confessional lines–presumably the same people who could never have believed that Nazis and Communists could possibly make an alliance as they did in 1939 or, for that matter, that democratic America and the Soviet Union could later have cooperated against Nazi Germany notwithstanding their considerable differences.