Iran has reportedly arrested opposition leaders Mir Hossein Mousavi and Mehdi Karroubi in an apparent bid to discourage the sort of mass protests shaking the Arab world from unfolding in Iran. Mousavi and Karroubi had been confined to their homes since pro-reform demonstrators took to the streets on Feb. 14, and more protests are still planned for Tuesday. Will detaining Mousavi and Karroubi help Iran stamp out an uprising before it happens, or merely fuel calls for change? (Watch a Euronews report about the arrests)

This will backfire on Tehran: The Iranian regime has already done "everything it can" to defeat the opposition, says Josh Shahryar at Enduring America. But if "propaganda, violence, intimidation... torture, and murder" didn't do the trick, arresting Mousavi and Karroubi certainly won't. If anything, this will push legislators and even some ayatollahs sympathetic to the Green Movement off the fence and into the opposition camp.

"Iran analysis: The regime arrests Mousavi and Karroubi in the race between fear and hope"

The opposition is already afraid: Two protests encouraged by Mousavi and Karroubi in February "did not totally paralyze" Tehran, which showed that the threat of a violent crackdown kept many Green Movement supporters home, says Ali Reza Eshraghi at Asia Times. Without more "courage and commitment," there will be no revolution in Iran.

"Revolution not in the cards in Iran"

Actually, it's the regime that's afraid: The mysterious "Mafia-style" kidnappings of Mousavi and Karroubi were signs of the "panic" among Iran's ruling elite, says Michael Ledeen at Pajamas Media. Supreme Leader Ali Khamenei "long resisted" the temptation to muzzle the Green Movement's leaders, out of fear that this would only "inflame the Iranian masses." The regime will no doubt follow up with "another huge mobilization of his thugs" at protests Tuesday. The question is, what opposition leaders waiting in the wings do next.

"The regime kidnaps Mousavi and Karroubi"