YOU could have heard a petit four drop. Count Paul Ignatieff paused during his speech at his youngest daughter's wedding reception in November, to make an impassioned plea for a world ban on landmines. Some 250 guests assembled in the marquee outside the family home in Dumfriesshire spluttered into their coffee. ''And that's the only commercial you'll get here today,'' concluded the newly-retired director of Unicef's European base in Geneva where he had led a team of 200.

The diplomat's proclamation came apropos an anecdote about the bride, Nicola. Based between 1973 and 1975 in Phnom Penh where Ignatieff was Unicef's representative to Cambodia, the family decided one day to venture into the countryside. ''We drove to a temple five miles from the city - we'd checked it was a safe area,'' explained Ignatieff. ''We passed 18 decapitated soldiers on the way and began to doubt our intelligence.''

Having arrived, Nicola sprinted into the undergrowth, relishing freedom as only a four-year-old can. She reappeared, screaming, in the grip of an elderly peasant yelling, ''Attention! Les mines!'' Two weeks later, Phnom Penh was surrounded; Ignatieff's Scots wife Katharine and the three children were evacuated to Bangkok.

Convinced about the nasty deliberateness of explosives which pollute more than 70 countries - one for every 16 children in the world - Paul Ignatieff became even firmer in his resolve to raise the profile of landmine awareness. ''The nature of war has changed. In 1900, civilians accounted for 10% of casualties, with military personnel 90%. Now it's the other way round. Because they're cheap, mines can be dropped by plane and are no longer mapped or controlled. There are an estimated 110 million of them.''

During a 30-year career with the United Nations Children's Fund, Paul Ignatieff had postings in nine countries, including Ethiopia, Sri Lanka, and Japan. In Cambodia, where his brief covered crossline operations in healthcare, primary education, emergency feeding, and water supply, he saw countless children with legs blown off. In Ethiopia he was appalled by the number of teenage conscripts missing a limb; and in his last post, Geneva, he was in a position to lobby at international level. He worked with Unicef's goodwill ambassadors, such as Danny Kaye, Audrey Hepburn, Peter Ustinov, and Roger Moore. ''In the early 50s, Kaye was sitting on a plane next to Unicef's executive director. Two months later, the star turned up at our New York offices to volunteer his services - he was our first ambassador.''

These celebrities shared with Ignatieff a strong sense of public duty. Born in 1936 in Edmonton, Alberta to a father with a doctorate in agriculture and a biochemist mother, Ignatieff comes from a long line of Russian public servants. His grandfather, a former minister of education to the Czar and married to one of the Czarina's ladies-in-waiting, was arrested by the Communist government. He was released because of his liberal sympathies and escaped to Bulgaria before arriving penniless in London. A note in the Times urged him to make contact with Barclay's Bank where Russian interests had amassed a fortune in deposit accounts. Equipped with the means to educate five sons, Ignatieff's grandfather directed them all into good works. Paul Ignatieff's father worked as an agriculturalist in the field of international civil service, moving his family to Canada in 1928. It was he who established

the Scottish connection.

In 1946, the United Nations Food and Agriculture Organisation elected medical practitioner and Scotsman John (later Lord) Boyd Orr as director general. Paul Ignatieff's father was Canadian government host to the conference which brought the body into being. He had met Boyd Orr professionally before; and now the Scotsman put Ignatieff's father in charge of global development of fertilisers. It was a far-reaching friendship. When Paul was 18 and, in his own words ''very mixed up'', he took time out to reappraise his future.

Boyd Orr's son-in-law, an international civil servant, invited him to farm with the family for a year in Brechin, Angus. ''That's when I fell in love with Scotland. I like the idea a man's a man for a' that.'' Ignatieff left to study French at Lausanne University where he met his wife Katharine whose family home near Moniaive they bought in 1988.

Despite family connections and hereditary title (''I've played it down all my life'') Paul Ignatieff entered international service by a circuitous route. He began his career as a market analyst, but, in keeping with family expectations, spare time was devoted to public service. Marketing management skills, and interest in international affairs, led to promotion from secretary/treasurer of the UN association in Toronto, to executive director of the Canadian Unicef committee in 1967. He negotiated the first Canadian government grants to co-finance Unicef projects in the developing world.

Ignatieff is proud that Canada, his homeland, is spearheading the drive towards a world ban on landmines. ''This month, 80 governments are meeting in Vienna to work towards a treaty in Ottawa this December.'' What Canada and its supporters seek to outlaw are weapons which kill or maim one person every 20 minutes. Since 1979, 45 rehabilitation projects set up by the International Committee of the Red Cross have manufactured more than 100,000 artificial limbs for 80,000 amputees. Owing to growth, a child amputee needs a new artificial limb every six months. And that's if he's lucky - many never receive a limb.

The effects of landmines are long-lasting in every sense. In Laos, children are still being maimed by unexploded anti-personnel bomblets dropped by the US a quarter of a century ago; Unicef estimates 120 million uncleared landmines are lying in wait. Their presence exacerbates hunger, endangers the return of refugees, and causes social ostracism. Millions of items of unexploded ordnance turn land into no-go areas. Caught up in this maelstrom of misery are tens of millions of children whose rights are violated from the moment they are born. Permanent blindness is not uncommon.

Yet there are those who argue emotional polemic blinds us to rational thought. The Princess of Wales entered an Angolan minefield cleared by workers from a charity which does not support a worldwide ban. This is because some ordnance experts believe it is simply unworkable. The main manufacturing countries (Russia and China) refuse to contemplate a ban; others, like Vietnam, rely on landmines for cheap industry. Critics of a ban worry five years down the road a treaty will be in place, but in name only, while a lot of money will have been squandered on a pointless campaign. They claim estimates of uncleared landmines are exaggerated to make clearance seem insurmountable.

Paul Ignatieff dismisses such arguments. ''You can dispute figures, but it's immaterial. The order of magnitude is something countries need to agree on. A maverick state will find itself isolated, subject to immense moral pressure.'' The answer, he says, is to ban manufacturing, sales, distribution, and movement of mines while facilitating the clean-up.

The British government recently presented proposals for a world ban to the Geneva Conference on Disarmament, a mechanism proven to be rather protracted. Britain manufactures AP devices (described in January's issue of Punch magazine). There is little doubt in the UK a ban would confront many vested interests.

Retirement to the Border sits uneasily on a self-confessed slave-driver who has lived life in the fast lane. For someone who survived an encounter with Pol Pot, fostered a Cambodian child and, with Katharine, entered fully into the life of international communities, peace and quiet demand a bit of adjustment. But Paul Ignatieff plans to deploy some of his prodigious energy into promoting Scottish produce, among other things. And he has much to look back on.

He recognises that, even in war, it is possible to find beauty. Before I left, he showed me an exquisitely carved brass game bird. ''It was made by a Cambodian child from a military shell-case,'' he explained fondly. ''Her father was a soldier and I bought it from him.''

Caught up in this maelstrom of misery are tens of millions of children