Major-General John Cantwell (Retired) is a fine, brave man with a distinguished military record. It just happens that Cantwell is suffering from post-traumatic stress disorder (PTSD). In July last year, he spent a week in a psychiatric ward and acknowledges that he is “”officially mentally unwell””.

Last week, Cantwell received considerable media attention after the publication of his book Exit Wounds: One Australian”s War on Terror.

Part of the journalistic interest in this memoir turned on Cantwell”s PTSD, which he acquired as one of the few Australians who participated on the ground during the first Gulf War of 1990-91. Cantwell was on exchange with the British Army at the time.

However, the essential media interest in Exit Wounds focuses on that part of the book where the former commander of Australian forces in the Middle East and Afghanistan asks himself the question: “”Is what we achieved in Afghanistan worth the lives lost and damaged?””

His answer is: “”No. It”s not worth it. I cannot justify any one of the Australian lives lost in Afghanistan.”” Exit Wounds is dedicated to the 10 Australian soldiers who lost their lives in Afghanistan while under Cantwell”s command in 2010.

On Monday last week, Cantwell was interviewed on Radio National Breakfast and Lateline. In the morning, he was asked by Geraldine Doogue: “”When was the tipping point for you … that the Afghan cause was not worth dying for?”” In the evening, Emma Alberici queried whether the gains Cantwell acknowledges have been made in Afghanistan “”have been worth the painful losses for Australia””.

On both occasions, the retired major-general rationalised his assessment as having stemmed from viewing the bodies of Australian soldiers “”on a slab in a morgue””. In Exit Wounds, Cantwell recounts how he personally identified the remains of each soldier. This was a kind and noble gesture. But it was also the action of a man who had been suffering from PTSD since the first Gulf War, some two decades earlier.

We live in a society that seems to be turning into a vast psychiatrist”s couch. The Facebook society encourages public displays of self-reflection on a massive scale. It seems likely that writing Exit Wounds, with help from journalist Greg Bearup, has had a cathartic effect on Cantwell.

However, it is far from clear that the families and friends of members of the Australian Defence Force who died or were wounded in Afghanistan will want to hear a major-general declare that the cause for which they fought was “”not worth it””.

Interviewed by Alex Sloan on 666 ABC Canberra last week, Cantwell complained some commentators have misinterpreted his position by presenting it as declaring that the dead had died in vain. His position is that the ADF in Afghanistan has “”achieved some good things … at enormous cost””.

Yet, for the grieving, it is a fine line indeed between a major-general saying someone died in vain or the cause for which they died was not worth it.

Clearly, writing Exit Wounds has been beneficial to Cantwell. For example, in the book”s epilogue he wrote that his “”sentences sometimes drift to a halt because [he] can”t remember the word for something””.

Yet Cantwell”s recent media performances were verbally flawless. There is clearly a role for disclosure and/or confession when recovering from a mental illness. It just does not have to take place in public.

The case for public silence is never more substantial than when politicians or public officials look back on the decisions they took that led to deaths and woundings in conflict. Robert S. McNamara (1916-2009) was a leading figure in the Kennedy and Johnson administrations, which committed US forces to Vietnam.

In 1995, McNamara wrote In Retrospect: The Tragedy and Lessons of Vietnam, in which he effectively called the commitment, in which close to 60,000 Americans died, a disaster. In 2003, he was the star of the documentary The Fog of War, another contribution to the they-died-in-vain syndrome.

In Australia, Malcolm Fraser, who held senior roles in the Coalition governments that committed Australian troops to Vietnam, effectively endorsed McNamara. In his memoirs and elsewhere, Fraser rationalises his change of mind as due to the knowledge he gained after the war that the US government and CIA was involved in the overthrow of the Diem administration in South Vietnam in November 1963.

A tall story indeed. I was in secondary school in 1963 and the US involvement in Diem”s assassination was discussed in class. It was no secret.

Former politicians have a special responsibility not to seek public forgiveness for latent regrets. Cantwell does not exhibit the self-indulgence of a McNamara or a Fraser. But publishers and journalists should take into account that Cantwell suffers from PTSD.

Gerard Henderson is the executive director of the Sydney Institute.