As a 2012 study of the case in the Personality and Social Psychology review found:
"Commenting retrospectively on this period, the prison governor recalled 'times when an officer would call me up and he was under so much pressure that I thought this is actually a prisoner I am talking to.'"
What's more, they ginned up significant support for Sinn Fein, the Irish republican political party. The British government was criticized for its stubbornness and cruelty, and the entire incident was seen as a black mark on Prime Minister Margaret Thatcher's legacy.
More recent hunger strikes have also proven moderately successful. In December, imprisoned human rights lawyer Nasrin Sotoudeh ended a 49-day hunger strike in an Iranian jail after authorities agreed to lift a travel ban imposed on her 12-year-old daughter. Two Palestinian prisoners held without charge ended their hunger protest in February after Israel agreed to release them in May.
And although they weren't prisoners, a group of Cuban dissidents did successfully agitate for the release of Cuban activist Jorge Vazquez Chaviano in September after an eight-day hunger strike last year.
Media attention seems crucial to the success of prison hunger strikes, so much so that Nelson Mandela once wrote of his hunger strikes on Robben Island in the 1960s and '70s,
"In order for a hunger strike to succeed, the outside world must learn of it. Otherwise prisoners will simply starve themselves to death and no one will know. Smuggled out information that we were on hunger strike would generate newspaper stories which in turn would generate pressure from support groups."
However, hunger strikes are most effective when the protesters' predicament presents an obvious solution, something Guantanamo doesn't necessarily have. President Obama pledged years ago to close the facility, but now that the detainees are banned from the U.S. and can't be sent back to their home countries out of fears that they'll join back up with terrorist groups, so they're effectively living in a geographic and legal limbo.
And as Scanlan notes, hunger strikes work best when bystanders and third parties are mobilized to join in -- something the Gitmo prisoners don't have the advantage of, at least not yet.
And the detainees also lack another crucial ingredient of successful hunger strikes: They aren't particularly sympathetic.
Saddam Hussein's 19-day hunger strike in captivity in 2006 was mocked by Americans and Iraqis alike (as was Iraq War protester Cindy Sheehan's fasting protest that same year, especially after she blogged about sneaking a coffee "with ice cream in it.")
"No matter how powerful the person, no matter how favorable the media coverage, if the willingness of the current political leadership and context isn't there, the success of the strike is not likely to come," Scanlan said. "We still live in a context where people for the most part are not sympathetic toward Gitmo prisoners."
The latest Guantanamo hunger strike is unlikely to result in the immediate closing of the detention center for the same reason that the facility is still open in the first place: The prisoners aren't compelling enough characters to bring about a major change.
(April 4 Update:) To underscore the idea that the trial and release of the Gitmo prisoners is not a top American political priority, there was a Washington Post-ABC poll last year that showed that 70 percent of Americans say they approve of President Obama's decision to keep open the Guantanamo Bay prison. From that same report, the New York Times' Andrew Rosenthal wrote "I've been told that the administration decided against taking a stand on this issue because their internal research indicated that Americans didn't care all that much. The Post poll, sadly, confirms that political diagnosis."