Needless to say, Chenoweth’s research builds on the philosophies of many influential figures throughout history. The African-American abolitionist Sojourner Truth, the suffrage campaigner Susan B Anthony, the Indian independence activist Mahatma Gandhi and the US civil rights campaigner Martin Luther King have all convincingly argued for the power of peaceful protest.

Yet Chenoweth admits that when she first began her research in the mid-2000s, she was initially rather cynical of the idea that nonviolent actions could be more powerful than armed conflict in most situations. As a PhD student at the University of Colorado, she had spent years studying the factors contributing to the rise of terrorism when she was asked to attend an academic workshop organised by the International Center of Nonviolent Conflict (ICNC), a non-profit organisation based in Washington DC. The workshop presented many compelling examples of peaceful protests bringing about lasting political change – including, for instance, the People Power protests in the Philippines.

But Chenoweth was surprised to find that no-one had comprehensively compared the success rates of nonviolent versus violent protests; perhaps the case studies were simply chosen through some kind of confirmation bias. “I was really motivated by some scepticism that nonviolent resistance could be an effective method for achieving major transformations in society,” she says

Working with Maria Stephan, a researcher at the ICNC, Chenoweth performed an extensive review of the literature on civil resistance and social movements from 1900 to 2006 – a data set then corroborated with other experts in the field. They primarily considered attempts to bring about regime change. A movement was considered a success if it fully achieved its goals both within a year of its peak engagement and as a direct result of its activities. A regime change resulting from foreign military intervention would not be considered a success, for instance. A campaign was considered violent, meanwhile, if it involved bombings, kidnappings, the destruction of infrastructure – or any other physical harm to people or property.

“We were trying to apply a pretty hard test to nonviolent resistance as a strategy,” Chenoweth says. (The criteria were so strict that India’s independence movement was not considered as evidence in favour of nonviolent protest in Chenoweth and Stephan’s analysis – since Britain’s dwindling military resources were considered to have been a deciding factor, even if the protests themselves were also a huge influence.)

By the end of this process, they had collected data from 323 violent and nonviolent campaigns. And their results – which were published in their book Why Civil Resistance Works: The Strategic Logic of Nonviolent Conflict – were striking.

Strength in numbers

Overall, nonviolent campaigns were twice as likely to succeed as violent campaigns: they led to political change 53% of the time compared to 26% for the violent protests.

This was partly the result of strength in numbers. Chenoweth argues that nonviolent campaigns are more likely to succeed because they can recruit many more participants from a much broader demographic, which can cause severe disruption that paralyses normal urban life and the functioning of society.

In fact, of the 25 largest campaigns that they studied, 20 were nonviolent, and 14 of these were outright successes. Overall, the nonviolent campaigns attracted around four times as many participants (200,000) as the average violent campaign (50,000).

The People Power campaign against the Marcos regime in the Philippines, for instance, attracted two million participants at its height, while the Brazilian uprising in 1984 and 1985 attracted one million, and the Velvet Revolution in Czechoslovakia in 1989 attracted 500,000 participants.