FORTUNATELY, few people know what it is like to see other human beings killed or severely wounded.

Most of us will never have to try to deal with the crushing guilt of surviving an enemy attack in which friends and colleagues died.

But for many who return to civilian life after being involved in conflict, the horrors of war cannot be left behind on the front line.

As you read these words many more British troops doing our politicians' bidding in Iraq are going through experiences that will change their lives irrevocably.

Martin Burd, of Byron Close, Malvern, is a fundraising volunteer for Combat Stress, a charity that helps ex-service people deal with post-traumatic stress and mental illness caused by their experiences.

He knows only too well how those who come into contact with violent death and destruction can be crippled by it for years afterwards.

After joining up in his 20s, he became a member of the Royal Electrical and Mechanical Engineers before transferring to military intelligence.

During his time as an undercover agent he saw service throughout the United Kingdom, Germany and the Far East.

Precise details of his experiences cannot be revealed, not least because he finds it difficult to talk about them, but they were to have a devastating effect on his later life.

As a lone operative, the awful scenes of death and devastation he saw he experienced on his own. The nature of his work meant he had to repress his memories and banish any sign of weakness - or face being taken off the job.

"Had I mentioned I was having problems, it would have immediately removed my security clearances," he explained, "So I just didn't talk about it."

However, after he left the service he could not forget what he had seen.

He suffered from chronic depression, hypertension and anxiety, and felt unable to cope.

That was where the Combat Stress charity stepped in. Finally, after 20 years, he could talk to someone about the things he'd seen - a counsellor paid for by the charity and trained to deal with the burden he had to unload.

"That's one of the problems that servicemen will have when they return from Iraq," he said. "They will not be able to describe to their families what they have seen, and neither will they wish to. They won't want to transfer to them the images they have seen."

By releasing the tension and gradually being taught coping techniques, Mr Burd can today lead what he regards as a "normal" life - although he still rarely sleeps for more than three hours.

For others, the post-traumatic stress can manifest itself through various mental or physical symptoms, including untreatable pain or even paralysis.

The fact that each individual has different combat experiences means the mental damage they have suffered can be difficult to recognise, let alone treat.

Since they helped him back into civilian life, Mr Burd has become a committed worker for Combat Stress. He is keen to emphasise its services are there not just for those returning from Iraq but for others who might have had past experiences triggered by television coverage.

Combat Stress also helps in applying for war pensions and gives specialist residential care that cannot be obtained anywhere else.

The organisation is currently trying to raise funds for a Midlands-based centre for occupational therapy, but needs donations to raise £500,000.

Anyone who wants more information on the charity, either to give a donation with Gift Aid or to make use of its services, should contact him on 01684 577302. The charity itself can be contacted on 01372 841600, at Tyrwhitt House, Oaklawn Road, Leatherhead, Surrey, K22 OBX or via www.combatstress.com.