The “Prague Spring” of 1968 was a gallant attempt at a nonviolent democratic revolution, but it was crushed by Soviet tanks. Eighteen years later, in the Philippines, the first “people-power” revolution succeeded, and since 1986 nonviolent revolutions have driven a great many dictators from power. The most recent was in Egypt, in February—but there never was a guarantee that these revolutions would turn out well.

It depends partly on how bad the ethnic and religious cleavages are in a country: Bulgaria and Romania were okay, but Yugoslavia was a blood-bath. It depends to some extent on how poor and illiterate the population is, although even very poor countries have made a successful transition to democracy. And it depends on good leadership and good luck, too. But it is the dominant political phenomenon of our time.

The revolution in the Philippines succeeded because by the late '80s, everything was happening in real time on global television. Oppressive regimes that had never had much compunction about killing people who challenged them didn’t feel confident about doing it before a global audience. They no longer felt free to use massive force unless the protesters gave them an excuse by resorting to violence themselves.

The Marcos regime that was overthrown in the Philippines in 1986 was a mere kleptocracy with little ideology beyond a vague “anti-communism”. When the infection spread to China in 1989, the outcome was different, because a disciplined Communist dictatorship was willing to kill large numbers of its own people in front of the television cameras. It understood that if it failed that test, it would not survive.

Less ruthless Communist dictatorships in Europe, longer in power and ideologically exhausted, did fail the test. The nonviolent revolutions that began in East Germany in November 1989, and ended Communist rule in the old Soviet Union itself by late 1991, could have been stopped if the local Communist regimes had been willing to follow the Chinese example, but none of them had the stomach for killing on that scale.

So about 350 million Europeans got their freedom and almost nobody died. At almost exactly the same time, the apartheid regime in South Africa released Nelson Mandela and began the talks that led to majority rule in 1994. A very well-connected African friend of mine told me later what had actually happened.

In late 1989, after the East German, Czech, and Romanian regimes had fallen with scarcely a shot being fired, the head of the National Intelligence Service, the South African secret police, went to state president F.W. de Klerk and warned him that if the African National Congress put half a million people on the street in Johannesburg, he would only have two options: to kill ten thousand of them, or to surrender power unconditionally.

If he didn’t like either of those options, he should start negotiating the transfer of power now. So Mandela was released, and eventually there was a peaceful transition from apartheid to majority rule.

Then there’s a long gap, perhaps partly explained by the fact that the number of dictatorships in the world had already shrunk considerably. An attempted nonviolent revolution in Iran in 2009 was mercilessly crushed. People worried that repressive regimes might have finally figured out how to counter nonviolent revolution. And then along came the "Arab spring".

So the technique is still alive, and it worked in Tunisia and in Egypt. On the other hand, it has been stamped out in Bahrain, whose fate resembles that of Prague in 1968. And while the revolt in Yemen has probably displaced the old regime, it has been very violent, and the new regime may be no more democratic than the old.

Same goes for Syria, and of course for Libya. There are no one-size-fits-all techniques for revolution or for anything else. But the desire for democracy, equality and fairness survives everywhere, and the least bad technique for trying to achieve those things is still nonviolence. Even if sometimes the revolution succeeds but the aftermath doesn’t.

The original “people power” revolution in the Philippines was followed by two decades of political turbulence. Yugoslavia splintered into half a dozen warring fragments. Russia, though it escaped mass violence, is not exactly a model democracy.

On the other hand, South Korea, Indonesia, and South Africa are now all democracies. So are Poland, Romania, and Taiwan. The aftermath may not be what most people hoped for in Egypt, and it probably won’t be in the case of Syria. But nonviolent revolution works often enough, and its results are positive often enough, that it is still the most hopeful political development of the past quarter-century.

The glass is half-full, and getting fuller. Even the most wicked and ruthless rulers must now take world public opinion into account, and we expect them to behave much better than dictators did in the bad old days. They may disappoint our expectations, but that is the standard by which they will be judged, and they know it.

Gwynne Dyer is a London-based independent journalist whose articles are published in 45 countries.