Playwright and former Czech President Vaclav Havel knows a thing or two about fighting what appears to be a losing battle against an oppressive regime. He wrote plays and philosophical tracts that critiqued the Communist regimes of Eastern Europe. He sat in prison for years for his words. And 21 years after seeing the Prague Spring crushed by the Soviet/Warsaw Pact military, he oversaw a bloodless revolution and became president of his country.
Havel offers a few words of encouragement for the Iranian supporters of Mir-Hossein Mousavi who think the Ahmadinejad government is trying to steal the presidential election:
Interviewer: You are well-known and highly respected by many people in Iran. What would you like to say to Iranians directly?
Havel: [I would tell them that] I sympathize with them, that I'm keeping my fingers crossed for them and I would advise them not to fall prey to skepticism if they do not achieve immediate results in spite of their efforts.
These efforts are important in and of themselves because there is virtue in working for a good cause. And these efforts can pay off later, God knows when, God knows how. But you cannot time it. That, at least, is our experience [emphasis mine; interview, "Havel Expresses Solidarity with Iranian Demonstrators," Radio Free Europe/Radio Liberty, 2009.06.15].
Even if your words and deeds do not produce the results—or the regime change—you seek, you do your soul good by fighting the good fight. That's pretty strong idealism.
Havel also recommends a dose of idealism for politicians outside Iran trying to figure out what to say and do:
...expressions of solidarity with those who are defending human rights, with students and others, are important. In general, oil should not be more important than human rights [emphasis mine].