After discovering Garry Trudeau's irreverent cartoon in the 'Washington Post', our former North America editor CONOR O'CLERYconvinced 'The Irish Times' to run it as well. It's easy to see why the strip is so popular

AN EARLY DOONESBURY cartoon strip, and one of my favourites, showed the US celebrity newscaster Dan Rather on assignment in Soviet-occupied Afghanistan, draped in designer robes and explaining to viewers how he had to sneak into the country disguised as a mujahideen. The final box revealed his film crew to be dressed in jeans and Ohio State T-shirts. It was this mixture of satire and entertainment that I came to relish after I first discovered the cartoons of the Yale graduate Garretson Beekman “Garry” Trudeau in the Washington Post on a visit to the United States in the mid 1970s. They were consistently irreverent and edgy, a daily challenge to the establishment with a fresh perspective and innovative ideas.

Later, as news editor of The Irish Times, I managed to convince Them Upstairs, as our cartoonist Martyn Turner, another Doonesbury fan, called our senior editors, to buy Trudeau's syndicated strip, which had by then won a Pulitzer Prize for editorial cartooning. Doonesbury joined Astérix and Tintin, both since long gone, on the back pages in April 1981. Two years later Trudeau took a 22-month break to create a Broadway musical of the strip. The outcry among readers at Doonesbury's absence was so great that The Irish Timeswas obliged to reprint old episodes. As Turner explained in a 1990 appreciation of his fellow cartoonist: "Them Upstairs suddenly realised they had a cult following on their hands."

Doonesbury had indeed caught on, and we soon became fully acquainted with the cast, centred around Mike Doonesbury and BD, his college roommate at the fictional Walden College, and expanded over the years to include an array of characters such as Mark, Zonker, Boopsie, Uncle Duke and the intrepid reporter Roland Hedley, whose early assignments included an exploration of Ronald Reagan’s brain.

"Doonesbury is like opening a Russian novel in the middle: it can take a long time to get your bearings," writes the comic-strip historian Brian Walker in an excellent retrospective, Doonesbury and the Art of G.B. Trudeau, published by Yale University Press to mark the cartoon's 40th anniversary, this year.

Noted for its liberal outlook – President George HW Bush once accused it of pandering to “a bunch of Brie-tasting, Chardonnay- sipping elitists” – the strip has been published in US newspapers since October 26th, 1970. It early on established a reputation for unsettling editors because, in Trudeau’s words, “it regularly introducing subject matter that they were quite certain did not belong in the comics”. A pop-culture enthusiast, he treated controversial issues in a ground-breaking way that prompted many editors to put his cartoons on the editorial pages rather than the child-friendly comic section – and to pull instalments when they got nervous. This happened when Doonesbury portrayed Rick Redfern and Joanie Caucus lying in bed together, and again when Andy, a classmate of Joanie’s, told her he was gay.

The constant theme was always timely social and political commentary. Jonathan Alter of Newsweek, to whom Trudeau gave a rare interview in 1990, described him “as much journalist as artist – an investigative cartoonist, Zeitgeist megaphone, flight attendant for his generation”.

Trudeau’s artistic methods were certainly original. He often ran four identical pictures of the White House with dialogue simply emerging from inside. Trudeau portrayed its tenants without their faces: George HW Bush was a tiny speck, Dan Quayle a feather and Bill Clinton a waffle. George W Bush was reduced to an asterisk under a Stetson hat, which was later replaced by a tattered Roman helmet when he took the US to war.

In response to criticism that he is harder on Republican presidents, Trudeau explained: “Satire has a point of view . . . Clinton may have rained disgrace on himself, but Bush did irreparable harm to the country. Why should I treat them the same?”

Not that he was easy on Clinton during the Monica Lewinsky affair, and a strip dealing with the sex scandal was dropped by many US newspapers because it included the word “semen”.

Doonesbury is the newspaper-cartoon equivalent of Jon Stewart's The Daily Show, the fake TV news programme that does a better job than real news channels of educating viewers about the hypocrisies of the political world. There have been predictable attempts at pulling him down. After Alter revealed in the Newsweek interview that Trudeau's pencil drawings were inked by a Kansas City-based artist named Don Carlton, the conservative Wall Street Journalaccused Trudeau of writing the text but not drawing the pictures.

Since then the cartoonist has preserved his pencil originals, many of which are reproduced in Walker’s book, giving the lie to the charge of “cartoon syncing”. A greater threat to Doonesbury is declining newspaper circulation. Comic strips do not have the same impact on the internet. Despite the loyalty of contemporary fans like myself, who turn to the back page even before leaving the newsagent’s, Trudeau fears the impact of his medium is waning as reading habits change. “Although I still love the little black-and-white drawings I’ve spent my life producing, I’m sceptical that a generation that’s grown up experiencing the world through screens will support comics as I’ve known them.”

His collaborator David Stanford argues that Trudeau is still “constantly responding to the world he is living in and commenting on it and having interaction with it”. The strip certainly remains topical. Trudeau has found excellent opportunities in the United States’ wars for his combination of biting satire with poignant plots. In 2004 BD became a soldier in Iraq, where he lost a leg. After awakening and finding this out he exclaimed: “Son of a bitch!!!” With typical timidity, several US dailies dropped this strip for its profanity. By highlighting the struggle of wounded veterans Trudeau has become the darling of the military rank and file but not of the war profiteers.

Last week Zonker’s Uncle Duke, a rogue in dark glasses inspired by Hunter S Thompson, was busy trying to corrupt Hamid Karzai to benefit his Blackwater-type military ventures. Trudeau’s original characters have aged with the baby-boomer generation: Mike’s son Alex is now in college and Joanie is in her 70s. But the strip retains a wide appeal both in the United States and abroad. In 2005, when the Guardian newspaper decided to drop Doonesbury, it received such a torrent of complaints that it was quickly reinstated, with an apology. Today Trudeau’s work is syndicated to about 1,400 newspapers worldwide, still portraying a US with a self-deprecating humour and compassion that we might otherwise miss. Trudeau, now 62, protests that he is not a cynic but an optimist. “I have a child-like faith in our better angels,” he says. “I believe we can get it right.”