Popular protests in China, feminist revolt in Iran, antiwar activism and possible sabotage in Russia—could the world’s three largest oppressive countries be teetering toward revolution or serious reform?

It wouldn’t be the first time. All three underwent multiple revolutions in the 20^th century: Iran in 1906 (parliamentary) and 1979 (Islamist); China in 1911 (republican) and 1949 (Communist); Russia in 1905 (constitutional), 1917 (Bolshevik), and 1991 (quasi-democratic imperial-breakup).

All those upheavals came as surprises. So, even though revolutions in those countries seems unlikely today, they’re not impossible—and the people in those countries, both the aspiring revolutionaries and those defending the present order, know this. They know that popular uprisings once took place in those countries. And this  awareness heightens tensions when they’re allowed to simmer and then boil.

Still, tensions usually don’t reach a boiling point. Sociologists and political scientists have analyzed the preconditions for radical change and one common conclusion is that, to be successful, revolutionary movements must have three elements: organization, a strategy, and a charismatic leader.

“Iran, China, Russia—the protests there have none of these,” said Larry Diamond, senior fellow at the Hoover Institution and author of several studies on the transition from authoritarian regimes, in a recent phone conversation.

The Chinese protesters holding up blank signs, the Iranian women ripping off their headscarves and shouting “Down with the Ayatollah,” the Russian anti-war activists—these are all remarkably brave people, risking serious jailtime or worse. But bravery and even crowded rallies aren’t enough to topple a regime or change a way of political life.

This is a major reason why Avril Haines, the Director of National Intelligence, recently said in an NBC News interview that Iranian officials don’t see the protests as an “imminent threat” to their rule.

However, Haines added, the Tehran government may face trouble in the long run because resistance to its edicts is  growing, schisms within its ministries are forming, and the economy continues to crumble. Besides that, much of Iran’s urban population—young, secular, plugged into Western news and culture, thanks to satellite dishes (which the regime long ago stopped trying to take down)—would be inclined to join a true revolution, if one began to take off.