So the slaughter goes on.

Health authorities in England are to be merged, and disappear altogether in Wales.

More tears will be shed, more sleepless nights endured and more high and low-flying careers will come crashing to a premature end.Happy days lie ahead.

Having survived the great reorganisation of 1974, and cheerfully fought in the battles of the 1980s, only to be handed the hemlock myself in the mid-1990s, what cheer can I offer those under threat?

Something really is wrong with an organisation which seems intent on periodically purging hundreds of managers it has trained at great expense over many years.

Any organisation's workforce is a major asset, and the NHS squanders its assets faster than a drunk in a casino.

In the 1990s, it came as a shock to realise that contemporaries with whom I had shared the promotions merry-go-round at interviews across the country had almost all disappeared without trace. Despite their early commitment to a lifetime in the NHS, nine out of 10 of my youthful companions' careers had not lasted 20 years, let alone 40.

What advice can I give to the young who may now feel the noose close to their necks for the first time?

First, accept that no-one cares - at least, no-one will care about you more than they care about themselves. Even your best friend is likely to stab you in the back if it means they might otherwise be left jobless.

Chief executives will be worried about getting jobs themselves.

What happens to you is low down in their priorities. Chief executives' public words of comfort and optimism are spoken with forked tongue and coloured by their need to ensure staff do not leave before they themselves have got a safe billet.

And some people are good at playing office politics. They will push themselves forward - whatever their merits - to ensure their survival; and survive they will. Remember, when times are bad, the good come last.

In any merger the winning chief executive is likely to take all. In truth there are no mergers, only takeovers; if your chief executive does not get a job, neither will the team, and this will reach all the way down to you. If by luck you do survive, remember when two organisations 'merge' it can take up to 10 years for the 'them and us' factor to disappear.

Of course, the young may dismiss this as the cynicism of a bitter and twisted older man picking the scabs from his half-healed wounds. But if you do not believe me, ask any of the over-40s (if you can find any) in your own organisation.

More fundamentally, one must ask why did the 1974 reorganisation, 1982 restructuring and mergers of HAs with family health services authorities in the 1990s fail so badly that each had in turn to be subject to major change? How many goes does the Department of Health need to get it right?

One answer lies in an inability to accept imperfection, though all complex systems are inherently imperfect. Each reorganisation has been designed to address the imperfections of the previous arrangements, and in achieving that has succeeded in creating new imperfections, which in their turn need to be addressed by yet further reconfiguration.

Human psychology is another reason.Ministers and senior civil servants cannot help but meddle.

It is in their nature. If they do not make changes, why should they exist? Give them an empty in-tray and they begin to fret that they should be doing something.

Ideally, the job should be mending something which is broken. But if they can't find it, they are quite happy fixing things which are not broken.

The NHS needs stability, not change. Its staff need time to learn to make the system work.

Instead they are subject to change upon change, devoting more of their energies to meeting the internal threats posed by mergers and closures than addressing their primary purpose - running a health service for the benefit of patients.

Perhaps stability is a forlorn hope in the modern world.Yet as long as the NHS continues in constant flux, the skills needed to run it will never have time to coalesce sufficiently to deliver a quality service.

But a few words of comfort to the young. In this reorganisation - and the next, and the next - those facing the uncertain future will find that not everyone is unhelpful and self-serving. The odds are that you will survive, at least this time.

And even if the odds are against you over a longer distance, take comfort that the many I have spoken with have reported that they have not only survived leaving the NHS, but - much to their surprise - found they have far been happier too.

Steve Ainsworth is a former primary care manager.