While watching the CBC's coverage of the earthquake in Haiti, I came across a short interview with a grief-stricken woman. She had lost two, I believe, of her children and was in agony.

Then the translator used a word that seemed odd in the midst of such a human disaster. While speaking of her children, the translation had her bewailing the loss of her "investment."

Today, we think of investments in terms of mutual funds, stocks, or even a house (if we own one). But children?

Of course they are investments, or at least were, for most people throughout history. The word is perfectly appropriate.

In times past, large families provided a labour pool, especially on the farm. For parents, they were your social insurance in a world before the welfare state.

A U.S. solider stands guard in front of an armored vehicle following an explosion in Kabul in January 2010. (Altaf Qadri/Associated Press)

If you invested well in your children, they would provide for you in your retirement.

The nuclear family

In those days, people knew that in every large family, a few children might die before reaching adulthood. So they spread out the risk by having as many children as they could, a very sensible policy.

But in today's developed world, family size has shrunk almost everywhere you look.

Instead of large families, richer, educated parents are having fewer children — in fact, only 1.56 for every woman of child-bearing age in Canada, according to the recent statistics.

We moderns have, for the most part, shrunk our biological "investments."

I was thinking of this link between the desperate Haitian woman and the declining Canadian family as I was interviewing historian Edward Luttwak for an upcoming episode of CBC Radio's Ideas.

Luttwak, a senior military analyst at the Centre for Strategic and International Studies in Washington, likes to say provocative things.

One of them is that war is particularly unappealing to us in the developed world because we have smaller families.

In an earlier age, if you lost a couple of your children to disease or war, you still had others to look after and to attend to you if you needed help.

Now, losing a favoured son on a battlefield can feel like the end of the world for today's much more compact nuclear family.

Highway of heroes

As I write, there have been 139 Canadian soldiers killed in Afghanistan over the past eight years. Each death becomes a banner headline and a trip down the "highway of heroes" as the body is returned to Canada.

The statistics vary but in the First World War, Canadians deaths totalled almost 57,000; in the Second, almost 23,000.

In some of the bloodiest battles of the First World War, like Vimy Ridge or Passchendaele or the Somme, so many thousands of soldiers were killed in a day that these battles could be fairly described as massacres.

This is not said to diminish the loss of a single life in our effort in Afghanistan.

Luttwak's point is simply that, today, each death in a modern war is almost untenable to the public. Even when our soldiers who die are volunteers, not conscripts, as they were in the brutal killing fields of the Western Front.

Limits of democracies

Luttwak is someone who defies easy political categories. He has been accused of being a right-wing courtier to the American military (for a time he was a military contractor and he fought as a volunteer in the Israeli army in 1967).

But he has come out resoundingly against the American interventions in Iraq and Afghanistan.

Not because he's a peacenik, but because he believes, as he said on Ideas, that "democracies can't occupy countries."

Well, actually, they could, if they wanted to be brutal about it.

Want to stop the sniping and the improvised bombs that are killing young American and Canadian soldiers? Simple, says Luttwak. Cordon off the population and create no-go zones along the Afghanistan border.

Or turn Afghanistan into a colony, as the allies did with the Germans, or as the Americans did during the occupation of Japan following WWII.

But going that route is long and costly and requires a total war that brings your enemies to heel, devastating them in the process, before they can be occupied.

As he has said elsewhere, the Romans and Nazis (and other empires) dealt with rebellions by massacring people. But democracies can't do that. And shouldn't.

A grand strategy

Luttwak is also a serious historian and not just an agent provocateur. His latest book, the occasion for the Ideas interview, is The Grand Strategy of the Byzantine Empire, a detailed study he's been working on for more than two decades.

Author and historian Edward Luttwak. (Photo from Harvard University Press website)

The Byzantine Empire was the longest lasting empire in history, 800 years. It was the eastern part of the Roman Empire and came to an end when the Ottoman Turks conquered Constantinople in 1453.

Because they were not all powerful, the Byzantines had to be smart in the running of their empire.

They oversaw a multicultural group of states and came to know the languages and history of the people under them.

Also, though their army was expensive and well trained, they fought only when absolutely necessary. Instead, as Luttwak points out, the Byzantines cunningly used allies to fight their enemies.

Those allies might have been your last enemy so it was a good idea not to have destroyed them entirely.

Rules of engagement

A Byzantine strategy for Afghanistan, he told us, would be to use indigenous forces in Afghanistan and neighboring countries, as the Americans did early on when they allied with what was called the Northern Alliance to drive the Taliban out in 2001.

You need smart intelligence, too. None of the CIA agents who were killed by a Jordanian double agent in Afghanistan last month spoke the local languages, Luttwak points out.

This would have amazed the Byzantines. In their court they had a full complement of translators and officials who knew every language in the empire.

The politically incorrect Edward Luttwak is not against war, per se, only bad ones, wars you can't win and that aren't sensible to fight in the first place.

In fact, he says too many wars (as in the Middle East) are fought without coming to a natural end.

Give war a chance, he seems to be saying. But he has his own rules of engagement.

For one, before you fight a war, be smart about it and fight only when absolutely necessary.

And for another, know the limits of what a democracy can do with its slender resources, in particular a population unwilling to sacrifice its precious children from ever shrinking families.

Luttwak can annoy and he likes to provoke, but he and the officials of the Byzantine Empire do have something to tell us, from the reaches of history.