He thinks his activism stems in part from his heritage. "It's in the folk memory of Irish people; it's famine in...the 19th century," he says. "In mid-1800s, we lost 2 million people to starvation."
"Irish people are quite informed on political matters," he observes, citing Irish women in particular.
One of Bono's most visible political gestures came in the early 1980s when he and U2 joined forces with Irish musician Bob Geldof for the Live Aid extravaganza raising relief funds in connection with the Ethiopian famine.
After Live Aid, Bono spent a month in Ethiopia. "It was a deeply and profoundly moving experience to be that close...in the eye of the storm of famine."
Even before that U2 aligned itself with causes: In 1983, its hit "New Year's Day," took inspiration from the Polish Solidarity Movement. The album War included "Sunday, Bloody Sunday," a reference to the Northern Ireland conflict. U2 also made a guest showing on the "Sun City" single opposing apartheid.
In the mid-'90s, as Bono accepted an MTV award in Paris, he chastised Jacques Chirac on nuclear testing. Last year's movie The Million Dollar Hotel, scripted by Bono, includes U2 song "The Ground Beneath Her Feet," with lyrics by Salaman Rushdie.
Recently Bono has been involved with the Jubilee 2000 project, which earmarked the millennium year for cancelling the debt of poor countries (adopting the biblical custom for jubilee years, every 49 years). Thihas allowed him to take a deeper look at the framework of poverty, the staggering debt owed by some Third World countries to wealthy Western nations, he says.
To find critical support, he scouted out the "Elvis"es of banking, as Bono calls them. "We had half of Harvard crunching numbers on this. Professor Jeffrey Sachs at Harvard...made himself available, would ring my home in Dublin at 9:30 in the morning, which meant that he was up at 4:30 working on it," he says. "We had some real backup with some real muscle."
Bono even met with political heavyweights like Bill Clinton.
Of course, politicians mixing with musicians can be like oil and water, Bono observes: "They're suspicious of us." Yet he points out, "Politicians are performers if they're any good."
Bono praises Bill Clinton - not because he plays saxophone - but for his foreign policy, for taking a leading role on the debt issue.
Yet years ago, one U2 album was critical of America. "In the '80s, the...America that we travelled through, I was both a fan or...a critic of. And our album The Joshua Tree describes both of those feelings, of foreign policy in Central America, everywhere; America seemed to be putting its big foot in everyone else's mess."
Today, though, Bono feels America intervened at the right time - at least on one occasion.
"Clinton came through in Bosnia at a time when Europe...was impotent and...indecisive," he says.
U2 itself even accepted an invitation to perform in Sarejevo.
"People in Sarajevo were really close to...what was going on in music. These people were watching MTV in shelters, while their houses were being exploded above their heads," Bono says. "They were turning the volume up...drown out the sound of the shelling."
"I lost my voice which wasn't helpful, but hey didn't seem to mind," Bono recalls of the Bosnia concert. "It was the first time the city had a glimpse of normality in a long time," he adds. "All the communities were represented at the concert," including Serbs, Croats and Muslims.
On all sides of the political spectrum, Bono has found unlikely political bedfellows.
"I wouldn't normally have much in common with Warren Hatch," Bono says, adding the senator warmed up to debt cancellation during a visit. "Conservative Republicans don't like the...inefficiency."
During his meeting with Hatch, the Senator shared some of his own songs. "Warren Hatch is a songwriter," Bono reveals. "There's musicians turning up everywhere. Alan Greenspan is a trained saxophone player....Tony Blair was in a band. It was a crap band. But he was a bass player in a rock band."
How does Bono gain such access to political leaders? "People are moved at a deeper level by music," Bono says. "Music has this shamanistic way of getting into peoples' souls....It thaws the most frozen of hearts and minds."
While Bono has donned a suit to negotiate inside places like the World Bank, he confides that "battle fatigues suit me better and barricades are much more romantic place for a rock 'n' roll singer."
"U2's music has always come out of a culture that includes politics... spirituality... sexuality," Bono says. "We're interested in the whole world."