A long time ago, when I started working in newspapers, I made one of many schoolgirl errors. I unthinkingly described a venerable cartoonist, a man who produces works of genius on a daily basis, as an “illustrator”. He was, quite rightly, incandescent with rage (if I tell you he was our very own Peter Brookes, you’ll understand how terrifying the episode was). For describing Brookes as a mere illustrator is a bit like saying that Kate Moss looks quite nice in a frock; or that Shakespeare wrote decent dialogue. A grotesque understatement, and so inadequate as to be insulting.

Older now, and only very slightly wiser, I now appreciate the difference between a cartoonist and an illustrator. Illustrators, well, they illustrate — most often someone else’s words or thoughts.

Cartoonists, however, are commentators in their own right. The only difference between a columnist and a cartoonist is that one uses words to express an opinion, whereas the other uses pictures. But while the writer has space (some might argue too much) in which to flesh out an argument, the modern political cartoonist must be able to state his or her case in a matter of seconds. A good cartoon is one that makes its waspish point as soon as the reader claps eyes on it. A brilliant cartoon is one that achieves that, and then reveals further nuances on closer inspection.

Like all social and political commentators, most cartoonists belong to their age. Never has the phrase “you had to be there” been more apposite than in the context of the daily satirical drawing. But there are some that transcend time and fashion. Even someone with little or no understanding of early 18th-century politics or society, for example, can still appreciate the draughtsmanship of William Hogarth; likewise, Brookes’s Nature Notes will carry a sting in the tail long after their subjects have disappeared from public view. Like all good satire, the cleverness stands out in its own right, preserved by the artist’s draughtsmanship.

By adopting such an outwardly childish form of communication — the language of the Beano and Mickey Mouse — to illustrate very adult issues, political cartoons are inherently subversive. They can be extremely disturbing for the same reason. A cartoonist can get away with drawing something the photographic equivalent of which would be completely unacceptable — or indeed physically impossible. When it comes to grabbing the viewer’s attention and getting the point across, there’s not much to beat it.

TransAtlant-ink is not just an overcomplicated pun; it’s the culmination of the British Council’s Young Cartoonist Project, which itself is part of a programme to celebrate ten years of democracy in South Africa. Ten cartoonists from Britain and South Africa were commissioned to produce work satirising each other’s political culture, the results of which will go on show next week at the Diorama Arts Centre in North London.

Much of the work centres, as you would expect, on the Blair/Bush relationship and the war in Iraq. This is of course well-trodden ground for satire, on which it is hard to find any furrow as yet unploughed.

But while the political sentiment behind much of the work deviates little from the accepted anti-American line, the execution is more refreshing. Themba Siwela’s Four More Years of Bush is clever, funny and cheeky, delivering its point swiftly and succinctly. Bethuel Mangena’s work, while graphically impressive, shows a less mature satirical brain, but one nevertheless not lacking in bite.

Rather more outstanding are those cartoons that address South African politics. Tanya Tier’s South African Defence Budget illustrates brilliantly her point about the paucity of funding to tackle HIV and Aids. Simultaneously serious and witty, the use of priapic missiles also deals a blow to South Africa’s male-dominated society. John Curtis’s You are Violating the Law that Prohibits the Promotion of Mandela is just really clever — dare I say almost Brookesian.

Critics might argue that if the West has the time, and resources, to spend on helping young South Africans, there might be better uses for them than funding a few cartoonists. Why aren’t our energies being directed towards Aids programmes or township investments? Well, it takes nothing away from the importance of helping in those terms to acknowledge the need to foster an open, questioning society in which South Africans themselves take the lead in shaping their destiny. Our own history shows that one of the vital signs of a healthy political culture is the open dissent recorded by satirists and artists.

Personally, I can think of no better use of funds than in sponsoring a group of people intent on haranguing a government which so far has failed to live up to its people’s hopes.

TransAtlant-ink is at the Diorama Arts Centre, NW1 (020-7916 5467), from Thurs to Dec 2