Political theatre flourishes at times of national debate; and the divisions over Iraq have inevitably activated dramatists. But what is significant is the variety of forms political theatre now takes. A play like Michael Frayn's Democracy, which moved from the National into the West End in 2004, is a brilliant fiction based on recorded fact: the spectacular rise and fall of Willy Brandt as West German Chancellor between 1969 and 1974. Frayn uses the infiltration of Brandt's office by an East German Stasi agent to explore not only Germany's geographical and spiritual divisions but also the mystery of human personality: especially the idea that we are all, as individuals, a coalition of competing interests. Democracy is not just a history play: it offers a vivid metaphor for the whole democratic process.

Alongside Democracy, however, there have been a number of topical documentary plays: pieces of ‘verbatim theatre’ in which the writer acts as editor rather than original creator. David Hare's The Permanent Way, co-presented by Out of Joint and the National Theatre, examined the human consequences of railway privatisation. Guantanamo, presented by the Tricycle Theatre and compiled by Victoria Brittain and Gillian Slovo, was based on the testimony of internees held without trial at the US prison-camp. And before that the Tricycle presented a whole series of ‘tribunal plays’ based on evidence given at enquiries into the death of Dr David Kelly and the killing of a young black teenager, Stephen Lawrence.

Satire has also made a recent comeback with Alistair Beaton in Feelgood and Follow My Leader analysing political spin and the Bush-Blair alliance. Theatre, in short, has increasingly become a public forum in which society is presented with an image of itself. But any idea that British drama is still the exclusive property of white, middle-class men has been dented by recent experience. Two black dramatists, for instance, have lately enjoyed high-profile productions of their work at the National Theatre. Roy Williams's Sing Yer Heart Out For The Lads, first seen in 2002 and revived in 2004, was a shocking, disturbing and highly up-to-date play about the kinship between racism and football: as a gang of amateur players gathered in a pub to watch England play Germany, virulent nationalism slowly gave way to an even more poisonous colour prejudice.

Kwame Kweh-Armah, a star of TV's Casualty, also wrote a wonderful play for the National Theatre called Elmina's Kitchen: set in present-day Hackney, it showed an upright older generation struggling to keep its sons from being seduced by the money and fake glamour of crime. And British-Asian dramatists have likewise been examining the social problems within their own community: most especially Tanika Gupta whose latest work, Hobson's Choice, wittily transposed a 1916 English comic classic to today's Asian small-business world.

These are only some of the many new voices that have made themselves heard in recent years. What is also significant is how many of the new voices are female: after centuries in which women dramatists were almost silenced by the male establishment, the tide has decisively turned. It's a process that began in the 1970s with the advent of Caryl Churchill and Pam Gems and that continued with the arrival of writers like Sarah Kane, Bryony Lavery and Timberlake Wertenbaker. But today women dramatists are no longer a disadvantaged minority and there are several new names to look out for.

Rebecca Lenkiewicz, for example, whose The Night Season was a rich tragi-comedy about a disintegrating Irish family. Or Moira Buffini whose commercially successful play, Dinner, was a bracing black comedy about the dinner-party from hell. Or Charlotte Jones who followed up her popular Humble Boy with The Dark which showed three neighbouring families temporarily united by a power-cut.

Scotland too, in addition to fine male writers like David Greig and David Harrower, has lately produced a bumper crop of women dramatists: most notably Rona Munro with a scorching prison-drama, Iron, and Linda McLean with a more lyrical piece, Shimmer, about three women who find themselves waterlogged on their way to Iona. And, even if Northern Ireland still seems a predominantly male preserve, Gary Mitchell's Loyal Women, seen at the Royal Court in 2003, sympathetically examined the dilemma of women marooned in the midst of a Unionist culture: in particular, the way they are simultaneously expected to be wives, mothers, nurses and unblinking, hardline patriots.

How, though, does one explain the existence of so much good new work? It is partly the result of so many venues – from London's Royal Court to Edinburgh's Traverse Theatre – actively commissioning new writing. It also reflects the injection of extra cash, some £25 million of new money, into the theatrical bloodstream. But I have a hunch that Britain's constant search for a distinctive identity – in particular the on-going conflict between tradition and modernisation, the weight of the past and the urgency of the present – is an active stimulus to the dramatic imagination. An American politician once famously said that ‘Britain has lost an empire but hasn't yet found a role’. But out of that perennial quest has emerged a host of exciting new plays.