Another key quote from your article...
"CNN: But shouldn't the U.S. be more vocal in support for the Iranian protesters?"
"Zakaria: I think a good historic analogy is President George H.W. Bush's cautious response to the cracks in the Soviet empire in 1989. Then, many neo-conservatives were livid with Bush for not loudly supporting those trying to topple the communist regimes in Eastern Europe. But Bush's concern was that the situation was fragile. Those regimes could easily crack down on the protestors and the Soviet Union could send in tanks. Handing the communists reasons to react forcefully would help no one, least of all the protesters. Bush's basic approach was correct and has been vindicated by history."