A This World documentary on BBC2 tonight (9.00 pm BST) produced a terrifying range of facts and events, but none more so than this statistic: more US soldiers have committed suicide in Afghanistan than those killed by the enemy.

The filmed account followed the exploits and psychiatric implosion of one platoon on tour in Afghanistan, and at the end of the process the viewer was left with the impression that all armies are indeed killing machines – but in this case, with a particular focus on their own soldiers.

Many of the platoon members were killed in action. Just as many got into trouble with the law on their return to the US. One private with obvious delusional problems and a drug addiction was simply discharged dishonourably on the day he confessed his condition to the army. He later teamed up with equally deranged vet colleagues, and together they killed two people without motive.

Another Mexican-American called Barco had problems as well. These too were ignored. At a party shortly after his demob, the bloke fired six shots into the ceiling. He got in his car, circled back – and fired four more shots. One narrowly missed a young man, but in the end nobody was hurt.

He was sentenced to fifty-two years in a State penitentiary.

All of these subjects were interviewed. None of them were dumb, and none of them looked to me like career criminals. What kind of institution is it that turfs out expendable human wrecks like these, and leaves the punishment of their derangement to civil courts without any support, or any sense of responsibility?

After a public outcry, the military held an ‘inquiry’ – the way whitewash artists do. We were shown a self-important man in fatigues assuring us that after “a deeply thorough investigation” it had been concluded that the army was not at fault.

Bollocks. The US military needs to ask itself:

* How these soldiers got access to the mind-altering drugs to help them get through the days of torment in action.
* Why their repeated requests for help were met with irresponsible prescriptions of ‘legal’ hallucinatory drugs.
* Why there was no outreach support for men severely mentally injured by months of horrific front-line action.

There are those who will harrumph and say they faced nothing more horrific than the horrors of World War II. There is a grain of truth in this; but these men didn’t elect to be born into a set of social mores within which there was zero expectation of that kind of horror. And lest we forget, our understanding of mental trauma has moved on a tad since 1945.

This was a gripping programme that held my bladder far beyond its normal limitations. If you have an Iplayer, watch it. It reminded me briefly of why I pay my TV license.