|The internet has helped to publicise hunger strikes internationally, creating drama and tension [AFP]
Two months into a hunger strike in Bahrain, Abdulhadi al-Khawaja is the latest international activist to revisit the tried, tested and dangerous approach to non-violent resistance.
His family worries that the human rights activist is in critical condition. The island kingdom has given him a lifetime sentence for anti-government political activities - against which the 50-year-old has been protesting.
By putting his body on the line to draw attention to a perceived injustice, Khawaja joins India's anti-corruption campaigner Anna Hazare, inmates in Guantanamo Bay prison and rights activist Khader Adnan in Palestine, in recent high-profile examples of starving for a cause.
"To a certain extent, this tactic is spreading," Shiv Visvanathan, senior fellow at the Centre for the Study of Developing Societies (CSDS) in India, told Al Jazeera. "It is a spectacle, a drama which creates some sense of horror from the outside. It is the ultimate act of desperation."
Sharman Russell, author of Hunger: An Unnatural History, isn't sure hunger strikes have become more common in the last year. Rather "the speed and reach of social media makes them that much more effective and powerful".
Strikers, including al-Khawaja, normally take water but eschew food. After about three weeks of not eating, the body begins literally eating itself, mining vital organs for nutrients. In the past, strikes which lasted more than 50 days have often been fatal.
"You are offering your body, this vulnerable, single human body, against the might of an institution or oppressive regime," Russell told Al Jazeera. "It is certainly something all of us can connect to. Even if we are sheltered and privileged in our personal lives, we are all vulnerable when we don’t have food."
Lessons from history
Early records of the tactic can be traced to India, occurring between 400 and 750 BC, but most of the quintessential cases studied by activists come from the modern era.
"The first hunger strikes in the West were by suffragettes [women who wanted the right to vote] in the United Kingdom, from 1909, and Irish Republicans in the United Kingdom from 1917," Michael Biggs, a sociologist at Oxford University, told Al Jazeera.
"The hunger strikes helped to give publicity to the suffragettes' cause, but they were ultimately not successful in winning votes for women."
Women won the right to vote after WWI, partially due to their contribution to the war effort, Biggs said.
Two Irish strikers, Terence MacSwiney and Thomas Ashe, died for the cause of an independent Ireland, helping to generate sympathy from Irish communities in the US and shifting public opinion against the British government.
"Because America was a democracy", popular pressure from Irish-Americans affected government policy in Washington, Biggs said. "This in turn was very important for the British government which needed the United States to act as an ally in the First World War, against Germany."
Hunger strikes in Ireland again gained widespread attention in the 1980s.
Relying on popular support and pressure, rather than mercy from the powerful, could be considered a wise move for campaigners, some analysts say.
Like other Irish dissidents fighting for independence, Macswiney and Ashe embarked upon hunger strikes while imprisoned. It seems to be a particularly common tactic for incarcerated people.
From Guantanamo without food
"Hunger strikes are constant features of prison life," Ramzi Kassem, a City University of New York law professor and attorney who has defended several inmates at Guantanamo Bay prison, told Al Jazeera.
One of his clients, Ahmed Zuhair, first started a hunger strike in 2005. A Saudi national, Zuhair, was captured in 2002 and was never charged with a crime by his American captors.
Prior to his release in 2009, Zuhair was frequently force fed, a procedure sometimes used against hunger strikers, which medical practitioners condemn.
US doctors are supposed to be bound by Article 5 of the 1975 World Medical Association Tokyo Declaration which states that force feeding hunger strikers is never justified.
It is impossible to determine if his hunger strike played a role in his release, but such gambits by prisoners are most effective when they "dovetail with a larger political message to the outside world", Kassem said. "They can be triggered by a particular cellblock incident, but really they are based on the larger injustice of Guantanamo itself."
Some of Kassem's current clients, including British resident Shaker Aamer, remain on hunger strike, protesting their indefinite detention and poor conditions. "The US government isn't claiming they want to prosecute him," Kassem said of Aamer.
Mahatma Gandhi, India's independence hero, is arguably the world's most famous hunger striker.
Capitalising on widespread national support for the tactic, anti-corruption campaigner Anna Hazare completed a 13-day hunger strike in support of a bill to tackle graft in 2011.
Nearly 30 per cent of Indian members of parliament have a criminal record or charges pending against them; few dispute that corruption is widespread and a worthy target for protests.
But the critics say the specific policies proposed by Hazare in the Jan Lokpal Bill are not the best way to address the problem showing the divide between hunger strikes as a romantic, morally powerful maneouver and politically dubious purposes for which they can be employed. Just because you are hungry doesn't mean you're right.
"Hunger strikes are not intrinsically noble," Russell said. "There are hunger strikes for all kinds of reasons. They are as complex as any political action."
Like other activists, hunger strikers often die before seeing the change for which they struggled.
"Having a martyr can make people more willing to make sacrifices for the cause, stiffening the resolve of sympathisers," Biggs said.
It's often difficult to tell how much momentum one particular action played in advancing a cause.
Back in Bahrain, Khawaja's daughter, Zainab, told Al Jazeera that her father faces two choices with his strike: "freedom or death". The Bahrani government, meanwhile, said his "health is good" in a statement released on Monday.
Professor Shiv Visvanathan thinks Khawaja's campaign is part of a larger international struggle for democracy and that hunger strikes will continue to be a key tactic for the weak in the 21st century: "In the age of technology, the body is the ultimate weapon."
Follow Chris Arsenault on Twitter: @AJEChris