In July 1948 Harold Pinter — now Sir Harold, one of our greatest living playwrights — left school. He was still living with his parents, at his boyhood home in Thistlewaite Road, Hackney, and getting ready to enrol at the Royal Academy of Dramatic Art in central London.

He was also about to turn 18 and become eligible for National Service. Not surprisingly, for someone who would go on to be such a high-profile pacifist, serving in the military was something the young Pinter definitely did not want to do.

But first he had to convince the authorities that he had good reason to be excused. His efforts to do so have just come to light in one of the files kept by the military recruitment division of the Ministry of Labour and National Service, held at the National Archives in Kew. The file fascinatingly documents this key episode in the playwright’s early life.

Most of the National Service files became public in 1998. It is uncertain exactly when the Pinter file entered the public domain, but almost incredibly, given the international scholarly interest in Pinter, it seems to have been overlooked.

Pinter’s statements, handwritten on official forms, are impassioned outpourings against war, the army and the post-war political scene. Their vehemence — the army is “an evil, stupid, sorrowful organisation” and “the mind that contemplates warfare is stupid, debased and deformed by fear” — anticipates by half a century the shocking brutality of Pinter’s polemical poems and speeches about the Gulf wars and the US army in Iraq.

In 1948 very few men of military age — one in 600 — claimed to be conscientious objectors. Boyhood friends of Pinter from Hackney Downs school joined up. But soldiering played no part in Pinter’s vision of the future.

He had already effectively left Rada after an unhappy start and as a backdrop to the crisis in his own life an international crisis was unfolding — the Soviet blockade of Berlin. For about a year, as the cold war began, he tangled with British officialdom, first as conscientious objector HXX 453, then as case number L26241.

To be a conscientious objector it wasn’t enough to hate violence. There had to be a coherent argument. Would-be COs had to appear before one of the tribunals that convened from time to time to hear their cases. Most were turned down. The objector could then go to an appeal tribunal. Pinter went through this process, and for each tribunal hearing he had to justify his position in writing.

His first statement is written on an NS 14 form — “Application to Local Tribunal by a Person Provisionally Registered in the Register of Conscientious Objectors”.

“I consider,” it begins, “that a world war at this time would be disastrous to mankind and would wreck civilisation. It is useless speaking of policies or sentiments or defence against aggression, for all these words will mean nothing in a final and eternal extinction.”

Primarily, Pinter said, his objection to National Service was moral: “To join an organisation whose main purpose is mass-murder, whose conception of true human values is absolutely nil . . . and whose result and indeed ambition is to destroy the world’s very, very precious life, is completely beyond my human understanding and moral conception. To take one human life is completely alien to my moral code.”

Signed simply “H Pinter”, the statement is dated December 8, two days before parliament voted through the National Service Acts 1948. The acts extended National Service: had Pinter joined up on cue he would have been in the first batch of new conscripts to serve 18 months rather than a year.

In 1988 Pinter said he would “certainly” have joined up in 1939 and that his position in 1948 had been refusal “to subscribe to the cold war”. No such distinction is drawn in his file. He rejects war under any circumstances — “on no account shall (a man) be the arbiter of another human’s existence by taking arms”, he writes, and “the history of mankind is marked by an eternal conflict between brainless, bestial savages fiercely grappling with one another, and men who comprehend and see the world’s truth and goodness”.