Soldiers are rightly cynical about the promises of politicians. They know that putting their life on the line provides no guarantees about how they will be treated when they return home. Creating a “land fit for heroes” has long been a cruel deception.

Even so, there is something particularly scandalous about the way the veterans of the Afghan and Iraqi conflicts are being treated. If they have suffered physical injuries, they have to take their place in the National Health Service alongside victims of drunken Saturday night brawls. But even injured soldiers fare well compared with thousands of veterans suffering posttraumatic stress disorder or other mental illnesses resulting from war.

Official figures show that 2,123 troops have been treated for mental health problems resulting from their deployment in Iraq since 2003. Army charities say many more are suffering but have fallen through the net. Afghanistan, soon to be Britain’s biggest troop deployment, is inflicting a similar toll. Combat Stress, the charity which helps to cater for the mental welfare of servicemen, says it is unusual to see such a high proportion of soldiers presenting with mental conditions so soon after active service. Normally it takes years for problems to emerge, suggesting that the hidden problem could be even larger.

The nature of the Iraq and Afghan conflicts, with an enemy that is often invisible and among a hostile local population, means that soldiers are subject to almost permanent tension. A roadside bomb or rocket-propelled grenade attack can be far more stressful than fighting a conventional enemy. And the unpopularity of the war in Iraq can only sap morale.

The treatment of military casualties has come a long way in the 150 years since Florence Nightingale helped to reform medical facilities in the Crimean war. Britain’s first military hospital and the Army Medical College date from that time. Then, a high proportion of injured soldiers died before they could be transported home. Now, with far superior battlefield medical treatment, survival is the norm; the challenge is dealing with the physical and mental scars of the war.

In Iraq fewer than one in 10 US soldiers with serious injuries has died, although a high proportion of the injured have been left with permanent disabilities. This compares with survival rates of one in four in Vietnam and one in three in the second world war. There has been a similar improvement for British troops.

That means that many more veterans return home with deep physical and mental scars. Anthony Bradshaw was a 19-year-old serving in Iraq at the time of the allied invasion in 2003. His experiences left him suffering posttraumatic stress disorder and he was discharged from the army, having received little treatment. Today he is at the mercy of an NHS that deals poorly with civilians with mental illness, let alone veterans.

Former soldiers are on 18-month waiting lists for therapy. They are given medication but little counselling or other assistance. Many are unable to work and end up homeless. Our veterans are being abandoned by the state that sent them to war. It is unacceptable. Since the Falklands war 25 years ago, nearly 300 veterans of that conflict have committed suicide, a death toll exceeds the 255 Britons killed fighting. We cannot allow that to be the legacy of Iraq and Aghanistan.

In America, where the treatment of Afghan and Iraqi veterans has also become a scandal, heads have rolled. Francis Harvey, the US army secretary, was forced to resign over conditions at the Walter Reed military hospital in Washington, as was the head of the hospital.

Here, the problem is less visible. Former soldiers suffering mental illness may bear no scars. But their needs are no less real than colleagues who have lost limbs. This government has been more willing than most to send soldiers into war. It is scandalously inept at picking up the pieces afterwards.