From the Jerusalem Post:
A week after Shin Bet head Yuval Diskin informed the cabinet that Hamas terrorists train in Iran, a commander in the extremist militia admitted as much to The Sunday Times.
Reportedly, the group has been sending gunmen to train with Iran's Revolutionary Guards for the past two years. Currently, the unnamed commander told the British paper, some 150 gunmen are being trained.
Hamas's members enter Iran via Syria and avoid having their passports stamped. Syria is also home to "more basic training" than that given in Iran. Gunmen deemed of outstanding quality receive extra training and return to train others in Gaza.
The most promising members of each group stay longer for an advanced course and return as trainers themselves, he said. Those unfit for combat return to "serve" in a research unit.
To read more about Hamas' admission about the group's involvement with Iran, the Times Online gives a more detailed analysis.
Anyway, so maybe that debunks the incorrect assumption that terrorists who adhere to different beliefs are unwilling to put that aside for the sake of fighting a common enemy, which in this case would be Israel. But Mccain specifically mentioned Al-Qaeda. While any connections to Iran and the notorious Al-Qaeda in Iraq seem more sketchy, it has been documented in the 9/11 commission Report that Iran may have looked the other way as AQ terrorists were passing through its borders. It's also been suggested that Iranian officials maintained contact with AQ's leadership.
Then there's the allegations that suggest Iran is supporting the Taliban in Afghanistan. If you listen to the critics, the Iranians would never do such a thing, seeing as the Taliban, like Al-Qaeda, are "Sunni extremists". But there's one thing Iran might regard as more of a threat than the Taliban--a democratic Afghanistan on its doorstep. Indeed, if the Afghan reconstruction efforts succeed, it could be a severe blow to Iran's attempts to clamp down on the pro-democracy movement inside its own borders. Therefore, is it all that surprising that the Iranian soldiers patrolling the border would be willing to pass off caches of weapons to Taliban insurgents if they knew if was going to be used to kill American and coalition soldiers?
In the end though, these people--Iran, Al-Qaeda, Hamas, and the Taliban--betray everything the religion of Islam teaches by murdering innocent people and justifying violence by holding a Koran in one hand, and an Ak-47 or a bomb detonator in the other. If they are okay with doing that, why would they care if they had to work together with a group that has hijacked a different denomination?
I do not know what Mccain was thinking when he made the statements. Maybe he has researched this issue and read through some of the reports (like the ones I've linked to) or maybe he just assumed that terrorists are all like-minded murderers in the end. One thing's for sure though, no matter what they believe, both Iran and Al-Qaeda are determined to prevent progress towards reconciliation in Iraq, and are willing to kill those who get in their way.