NOTE: The following review dates from September 2003 and this production's original run at the National's Cottesloe Theatre.

Michael Frayn's multi-award winning 1998 three-hander Copenhagen was set in 1941, at the outset of the Second World War, and centred around the real-life visit of a German nuclear physicist to his Danish colleague in the Nazi-occupied city of the title.

In his latest play, once again directed by long-time associate Michael Blakemore, Frayn returns to the fertile field of 20th-century European history. Back in Germany, nearly 30 years after the events recorded in Copenhagen, the country - and its citizens - has been split down the middle, divided between East and West, right and left, past and present. The capitalist West has managed to rebuild itself from the rubble into a world power, while the communist East remains veiled behind the Iron Curtain, grey and dull but reassuringly simple.

Democracy begins with the election of Social Democratic Party leader Willy Brandt as West German Chancellor and follows his turbulent course in office over the next four years, during which "the great peacemaker" implores his countrymen to have "courage to show compassion" and to accept reconciliation with their former enemies in Eastern Europe. Along the way, his personal assistant Gunter Guillaume organises Brandt's schedule, cheers him, comforts him - and spies on him for the East German secret police.

As Guillaume, Irishman Conleth Hill is virtually unrecognisable from his last London outing in Stones in His Pockets. Seemingly greyer, plumper, more unassuming, Hill plays well the oleaginous "little man" who grows bigger, bolder and ever more conflicted in the "sunshine" of his idol's smile.

And Roger Allam is utterly convincing as the subject of Guillaume's devotion and betrayal. With the cast of his eye and the turn of his lip, with his delivery of Brandt's trademark silent gestures and speeches, with his very stillness, Allam conveys the immense gravitas that attracts seas of upturned faces even as it belies moments of self-doubt and deep despair. His is a great leader indeed.

Special mention, too, to David Ryall who, in a strong, all-male ensemble, impresses as Brandt's opportunist party peer Herbert Wehner, and to designer Peter J Davison, whose two-tier office set, with its walls of colour-coded files, keeps its own nifty secret till the end.

In the programme notes, Frayn writes that "complexity is what the play is about". For our sake, his script and Blakemore's direction succeeds in simplifying the complexities of German history and politics, with Hill providing helpful asides to Steven Pacey's Stasi agent. But the complexity of "human arrangements and of human beings themselves" that lies at the heart of Democracy, is left for us to judge. Is the lesson to "trust no one" or to follow the maxim that "we must trust each other...there's no other way we can live"?

Brandt may not have been able to trust his aide, but ironically, it was Guillaume's reports that gave the East the confidence to trust Brandt. In the play's closing moments, the evocative sounds of hammers chipping away at the Berlin wall remind us how that trust ultimately paid off.

- Terri Paddock