As often, Lord Owen has voiced the crucial question, this time one that goes to the heart of the malaise over Britain’s troubled role in Afghanistan. Was it not time, he asked, to appoint a political heavyweight as defence supremo at a time when leadership of the war in Afghanistan has never been so crucial — or so lacking?

The Secretary of State for Defence was once one of the great offices of state. Any government’s basic obligation is to ensure the safety of the realm. And no one bears more responsibility for the task of protecting Britain’s interests and ensuring that the Armed Forces have the manpower, means and morale to do their job than the man who heads the Ministry of Defence.

Yet under Labour this office has been steadily and demeaningly downgraded. Bob Ainsworth, a name that most Britons would struggle to recognise and chosen because he was the least worst of four middle-ranking Labour MPs, is only the latest in a series of politicians whose tenure at the MoD has been as brief as it has been undistinguished. George Robertson, the last Labour Defence Secretary of any weight and influence, spent no more than two years there before being offered a peerage and sent to Brussels as Secretary-General of Nato. Since then, the office has been no more than a parking slot for ministers on their way up or down. Geoff Hoon never mastered the job. John Reid, ambitious and capable, arrived from Health, spent a brief year at Defence and was then moved on to the Home Office. Des Browne’s appointment symbolised Labour’s disdain for the job, which was combined with that of Scottish Secretary — a move not only insulting to the Armed Forces but disastrously short-sighted at a time when Britain was attempting to fight two wars. John Hutton was admired in the corridors of the MOD, but no sooner had he learnt his way around them, then he stood down. Indeed, not since Denis Healey has Labour appointed a man able to bring the necessary commitment, continuity and intellectual calibre to the office.

In the United States great decisions on international policy are shared between the White House, the State Department and the Department of Defence. In this country the triumvirate is Downing Street, the Foreign Office and the Department for International Development. It is telling that Douglas Alexander, both senior to Mr Ainsworth and closer to the Prime Minister, was retained at DFID rather than moved to the MoD, even at this time of war.

Nothing could better underline this refusal to recognise the needs of defence than Mr Brown’s intervention in March over force levels in Afghanistan. As the Obama Administration was preparing to deploy an extra 21,000 troops, General Sir Richard Dannatt, the head of the Army, made clear that Britain also needed at least 2,000 more troops to make any headway in Helmand. (If he had been given any encouragement he would have submitted a request for 4,000). The uniformed military eventually presented a request to increase troop levels to nearly 10,000. But Mr Brown and the Treasury overruled advice from the chiefs of the Army, Navy and Air Force as well as his Defence Secretary and insisted that no more than 700 extra men would be sent out — and then only for the duration of the Afghan election campaign.

Little wonder, in the light of such intervention, that the status of the MoD is low. Little wonder that the public has strong doubts about the entire Afghan strategy. Little wonder that, for all his protestations, Mr Brown’s defence record is deplorable. When the last Cabinet list was published, Mr Ainsworth’s junior status meant Defence was placed 21st. What does that say about the regard in which the office is held?