This is what's happening. A new Conservative prime minister is taking on the public sector. There are violent protests by students, as well as mounting industrial and social unrest. Against this background, a new generation of playwrights attacks class privilege and capitalist greed. Experimental theatre-makers incorporate film, dance and circus techniques into shows presented at odd hours in non-theatre spaces. The classics are being reinvigorated by discoveries made on the burgeoning fringe.
I speak, of course, of the early 1970s, when a new generation of young, radical playwrights - inspired by the late-1960s student revolt, and enabled by the abolition of theatre censorship - was writing plays to be performed in pubs, basements, attics and out of the backs of white vans. One such troupe was the General Will, for which I wrote a series of cartoon plays about what felt like an proletarian insurrection against the 1970-74 Edward Heath government. We also participated in the countercultural Bradford Festivals of 1970 and 1971, which featured a Howard Brenton play about Scott of the Antarctic performed in the city's ice rink, a pagan child-naming ceremony in the Wool Exchange and a full-scale mock-up of an American presidential election - with live elephant - in the streets of the city. Elsewhere, Peter Brook was presenting A Midsummer Night's Dream in a white box set filled with actors spinning plates, stilt-walking and flying on trapezes.
So, if the theatre I entered in the 1970s bears an eerie similarity to British theatre now, what's different? Well, in the interim, the National Theatre moved into its new building and a network of other London institutions - among them the Donmar, Almeida, Arcola and Globe - became part of a new theatrical settlement. Provincial theatre was also transformed by directors from fringe companies, which presented increasingly distinct programmes of work, discovering neglected historical canons from Europe and beyond.
But the biggest change was and is in the range and quantity of new writing. Two years ago, I contributed to a report that collated box-office information from 65 of Arts Council England's 89 regularly funded theatres, and found that, between 2003 and 2008, the volume of new work presented had more than doubled, from roughly 20 per cent to 42 per cent of the repertoire. In his definitive study of today's British theatre (Rewriting the Nation), Aleks Sierz estimates that there were 3,000 new plays produced in Britain during the 2000s, double the number in the previous decade.
The growth of new writing has been largely at the expense of classic work. It has involved an increase in new writing for children and a considerable growth in plays by black and Asian playwrights. But the sheer variety of work makes it hard to identify a general theme. It was easy to label the kitchen-sink dramatists of the 1950s, the state-of-England playwrights of the 1970s, the women dramatists who emerged in the 1980s and the in-yer-face school of the mid-1990s. The plays of the Noughties range in setting from Kabul to California, their subjects from the NHS and education through to celebrity culture and Islam. As Sierz puts it, late-20th-century British new writing was essentially Newtonian, proceeding in linear fashion on the principles of cause and effect. In the 2000s, it went quantum.
That said, the war on terror is to the British theatre of this century what the crisis of masculinity was to the theatre of the 1990s and feminism to the 1980s. Initially, the theatrical response to 9/11 was plays not just based on, but consisting of, interviews, documents or transcripts of trials. More recently, playwrights have felt able to present their take on the post-9/11 world. In dozens of plays, that has entailed a critique of liberal interventionism. The National Theatre alone has presented four plays that deal with the baleful results of trying to impose "western values" on African countries.
So, how will contemporary British dramatists deal with a political crisis that increasingly echoes that of the apocalyptic early 1970s? It's too early for plays about student protests, the Arab spring, phone-hacking or the riots to be in production, but work about some or all of these subjects will be in the pipeline, just as Lucy Prebble's Enron anticipated the financial crisis and Laura Wade's Posh anatomised the making of the current leadership of the Conservative Party. The huge cohort of politically aware playwrights of the Noughties, and those from earlier eras, are as well equipped to deal with the momentous events of 2011 as they have been with New Labour, the personal debt crisis, the BNP, religious fundamentalism, the war in Iraq and - increasingly - climate change.
There are, however, signs of dark weather ahead. The idea that the current outbreak of Rattigania heralds a flight from the gritty present back to the soft certainties of drawing-room comedy is probably exaggerated: Terence Rattigan is a great dramatist, his best-known work never went away and the emblematic kitchen-sink playwright, Arnold Wesker, is also enjoying a summer of major revivals, without the benefit of an anniversary. But one obvious and one less obvious development threaten the rise and rise of British new writing.
The obvious one is the cuts. Most theatres specialising in new writing - like most theatres - faced the statutory 11 per cent chop, but equality of misery cuts deeper into smaller institutions. The double cut imposed on regional companies reliant both on Arts Council and on local authority funding hit small-scale theatre outside London particularly hard. And, amid the entrails, there were indications that new writing had suffered disproportionately. Two big writing development agencies - in the East Midlands and the north-west - were cut entirely, and the Almeida and Max Stafford-Clark's Out of Joint (the major national tourer of new work) bore cuts of 39 and 28 per cent respectively.
The less obvious threat comes from a bias against text-based work in the theatre - including new writing - which began in the academy. In the vibrant early 1970s, the individually written new play and the collectively created performance piece were seen as different but complementary. In the past 20 years, British
academics have developed a theoretical justification for the claim that the individually written play is incapable of challenging linear narrative and straightforward characterisation (as if the work of Martin Crimp, Caryl Churchill and Sarah Kane had never been written). In parallel, advocates of site-specific theatre see the writer of the theatre text as the class enemy. One such critic describes individually written plays as "commodity theatre", another as "factory processed . . . capitalist and conquering", neither of which is intended to be a compliment.
This view has seeped into the public realm. Ten years ago, the Arts Council produced a policy document which argued that text-based drama - everything from Aeschylus to Ayckbourn - was in terminal decline. Hence, in the Arts Council's 2007 theatre policy review, new work was dropped as a priority, in favour of "experimental practice and interdisciplinary practice, circus and street arts". But while the volume of site-specific, devised and physical theatre has grown in the past decade, the main story remains the ascendancy of the individually written new play. The divide between performance and text-based theatre is being breached by playwrights such as Bryony Lavery, Abi Morgan, Dan Rebellato and David Greig, who have worked with performance companies such as Sound and Fury, Frantic Assembly, Lightwork and Suspect Culture.
It is possible that a combination of government cuts and cultural fashion may make the first decade of this century look like a lost golden age of new writing. But, seen from a 40-year perspective, it's a huge success story. Like our predecessors at the Royal Court in the late 1950s, those of us who started out in the 1970s thought theatre's main business should be presenting new plays about public subjects set in the modern-day world. We're a lot closer to achieving that ambition now.
David Edgar's new play, "Written on the Heart", opens at the RSC's Swan Theatre in Stratford-upon-Avon on 27 October