In David Hare's 1983 play Map of the World a character pores over The Times crossword, wondering what seven-letter word begins with "z" and means "the plague of the earth". When someone else suggests that the solution is "Zionism", an almighty row breaks out, in which Israel is accused of squandering the sympathy gained by the Holocaust by "creating a vicious, narrow-minded, militarist state". Though hostilities taper away when it is discovered that the "z" should really be an "s", that odd, barely relevant little episode left me wondering if Hare wasn't surreptitiously feeding us his own doubts about the Jewish homeland.

Well, Via Dolorosa is a direct if belated answer to that question, coming as it does in the form of a 90-minute account of Hare's visit to the Holy Land narrated by the dramatist himself. It is that, yes, Israel is in many ways a dangerous, unloveable place which has come to define Jewishness in terms of land rather than ideas, things rather than people. Indeed, Hare implicitly accuses the nation's present rulers and its religious Right of themselves contravening the Commandment against idolatry. On the other hand, he is observer and artist enough to acknowledge that this scarcely sums up the complexities of a region where, as a friend remarks, "we experience events and emotions in a single day that would keep a Swede going for a year".

A satisfactorily disoriented Hare is soon sweeping through desolate Arab land on a four-lane highway to a tiny settlement that "but for the barriers and armed guards might be one of those towns Steven Spielberg uses when he wants to show aliens disrupting total suburban normality". There he confronts the belief that the Bible is a land registry determining ownership forever, and that Rabin was a traitor who organised his own assassination - and all from the mouths of generous, kindly, warm people.

But he finds as much dissent, and as little belief in the peace process, when he crosses into what feels to him like Bangladesh. The corruption of the Arafat regime is much mentioned, as is the dangerous disillusionment of the young men who fought the intifada.

Palestine is as divided against itself as an Israel polarised between the younger Begin, with his "2,000-year yearning to go home", and Rabin's ex-colleague Shalamit Aloni, "a manic-depressive Melina Mercouri" who sees Israel - well, rather as a vicious, narrow-minded, militarist state.

Hare does not try to embody his many interviewees. Indeed, he doesn't act at all. He simply stands on what remains a bare stage, at first making nervous, jerky gestures, gradually becoming more confident, and ending up offering a fluent, engrossing, often funny, ultimately sombre monologue about a search for - what?

Insofar as it is for faith and hope, it leaves him deeply frustrated, for he finds little but discord and pessimism. Nobody, Jew or Palestinian, has an answer to his repeated question, "what is the way forward?". But insofar as the search is for understanding, it is rewarded - and, you'll find, rewarding to encounter in the theatre.