The Agreeable World Of Arnold Wallace: In my day MI5 was a club you wanted to belong to

THEY DID these things so much better in my day. Those of us who were once proud to do our bit for our country - I'm sorry, but I'm not prepared to go any further than that - are heartily sick of the sight of the flabby, good-for-nothing face of Mr David Shayler, a man better suited to the part-time profession of breakfast "deejay" (dread word!) than the honourable position of British spy.

Has it really come to this? When I was up at Oxford, a senior bachelor don would screen all potential recruits for the Secret Service with a fine-tooth comb. I well remember - what? 40, 50, years ago? - standing in that dons' room, with its musty smell of books, mackintoshes and old- fashioned posing-pouches, being screened from top to bottom with that infamous fine-tooth comb. "Ooh! Stop it! It's hurting!" I would yelp. But we were both made of tougher stuff: it was an hour or more before we fell in a heap, exhausted, yes, yet strangely exhilarated.

Some years later, I chanced upon the top-secret report on me while sifting through the bottom drawer in a topless bar in Middle Wallop. "Poor with people, untrustworthy, given to bouts of heavy drinking and with unchecked tendencies in most directions," ran the report. "Highly recommended for senior position."

For 30 years I was a high-ranking officer in MI5, but to the outside world I was a distinguished journalist, twice shortlisted for the Pipe Smoker of the Year Award, whose long-running column "I Know Something You Don't Know" in the News Chronicle was a model of discretion. "Mr Profumo may have acted unwisely, perhaps even a trifle foolishly," I commented at the time of the eponymous scandal, "but he knows and I know that many aspects of this affair are not as they appear to `Mr Joe Public'. Alas, the details must remain under lock and key, available only to those of us in a position to be trusted with them. But take my word for it: if you knew what I know, you would know enough to realise that there is no reason at all why people like you should know any more than you know already."

In those days, one could be trusted with government secrets of the utmost importance without feeling the urge to rush willy-nilly to the world's press with them. In my 30 years in espionage, I sold secrets to a foreign power only twice, and on both occasions I was under clear instructions from my accountant. And even those who chose to push the rules of MI5 a little too far - I'm thinking now of Philby, Maclean, Blunt, Burgess and so forth - at least did it in a proper suit and tie, unlike Mr Shayler, with his unkempt hair, grubby T-shirt and mouth laden with sweetmeats and bubblegum.

Contrary to popular belief, espionage was a very clubbable profession. A group of us from East and West would meet in the Travellers Club on the first Thursday of every month throughout the Fifties and Sixties to swap tips, anecdotes and codes. Of course, there were the very strictest rules for preventing any major breach of secrecy. If my opposite number in the KGB should ever lean over his prawn cocktail and ask me, man to man, whether there was any truth in the rumour that we in MI5 had succeeded in placing a mole in a very senior position in the Kremlin, he would be duty bound to accept my limited reply of a nod and a wink and two taps with the right forefinger on the nose. But I would similarly be bound to listen to his supplementary question, which would probably go along the lines of "Does his name begin with an `A'? A `B'? A `C'?" and so on, though I would only be obliged to reply to each question with the words "Colder" "Warmer" or "Ouch, Vladimir - you're so hot it's scorching!!!"

When did things begin to go wrong? To my mind, it was when we let Kim Philby go. Though he had strayed off the beaten track, we could ill-afford to lose a public-school-educated man of his quite exceptional charm and ability. If he wished to spy for the Russians as well as for us, we should have tried to accommodate him rather than sending him packing. After Kim left, the "Sixties" (dread decade!) came upon us, the floodgates were open and even the Secret Service was drowned in the tidal wave of classlessness. Anyone was allowed in: Peter Wright with his absurd hat, Michael Bettaney with his pasty face - and now the abominable Shayler. Who next? Mr Chris Evans? Miss (Mssss!) Geri Halliwell? No, treachery is not what it was.