War is the expression of politics by other means.

That quote by Carl Von Clausewitz comes from his classic "On War," a book well worth revisiting as bloody conflict looms in Iraq.

The stated policy of this impending Iraq bloodbath -- a regime change -- is often considered somewhat misleading. One often-stated potential underlying reason is oil. A second theory holds that President Bush wants to permanently change the situation in the Middle East by planting a Western-style democracy right in the middle of the Arab world. It's the domino theory in reverse -- democracy will spread.

This may be noble and it may look good in a William Safire or George Will column, but history suggests that at best it is a ludicrous idea, and at worst, a delusional fantasy with potentially tragic consequences.

There's no history of democracy in that part of the world, and if current repressive regimes such as Saudi Arabia or Egypt opened up political discourse, they'd be fueling the extremists they are currently trying to suppress.

Clausewitz and "On War" gained new converts in the American military after Vietnam, and for good reason. American military planners always considered war and politics to be totally separate. Clausewitz stood that argument on its head, and what he wrote in 1832 rings true with the Iraq situation today.

"When people talk, as they often do, about harmful political influence on the management of war, they are not really saying what they mean. Their quarrel should be with the policy itself, not with its influence. If the policy is right -- that is, successful -- any intentional effect it has on the conduct of the war can only be to the good. If it has the opposite effect, the policy itself is wrong."

Clausewitz used as examples the grand -- and nasty -- wars of history. That's bad news for products of American public schools, who probably couldn't tell you who Napoleon was, but the good news is the theories still apply.

For instance, how do you define victory? Is it the destruction of the enemy army? Is it the occupation and subjugation of enemy provinces? Is it the capture of the enemy capital? Clausewitz talked of "centers of gravity" -- if the leader got his gravitas from the army (Alexander the Great), then defeating the army meant defeating him. If the base of power is the capital, seize the capital.

Consider, then for a moment, the war on terror. The U.S. conquered Afghanistan, but it didn't subjugate it; the U.S.-protected president rules in the liberated capital, but warlords and fiefdoms still dominate the countryside. The stated target, Osama bin Laden, remains at large. So what did we win? According to Clausewitz, we won nothing.

And now we have a war machine building in the Persian Gulf, and a fuzzy policy that sounds like a script for a movie remake -- Mr. Smith goes to Baghdad.

Which leads us to three final thoughts.

First, you can "google" Clausewitz and find copies of "On War" online. Be advised, however, that it is dense -- incredibly dense. It reads like philosophy, with steadily advanced arguments and lots of therefores; Tom Clancy is safe.

Secondly, Clausewitz's philosophy stems from the relationship of three elements of war and the factions most involved in each -- the government, which makes the policy; the army and its generals, which execute the policy; and finally, the people.

We know how things are stacking up with our government and generals. But considering recent peace marches, it is a now a very legitimate question to ask if these Clausewitz-converts have forgotten the third leg of the trinity.

Finally, a buzzword alert. Most folks are familiar with the term "for of war." Clausewitz used the term "friction" to describe how things get gummed up once bullets start to fly. The word is already creeping in to talking head soundbites. It's an excellent term, and Clausewitz defined it this way:

"Everything in war is simple, but the simplest thing is difficult. The difficulties accumulate and end by producing a kind of friction that is inconceivable unless one has experienced war."

***

G.L. Marshall wishes to remind people that Sun Tzu, in his "Art of War," says the truly great generals gain their victories without battle.

Mr. Marshall, in his longest Web postscript ever, also feels compelled to offer the denseness of Clausewitz's work, and how it relates to his trinity of warfare, to anyone tempted to go Google him. And for people who believe in information in the public domain, remember I couldn't republish this if he was born in Walt Disney's time:

War is more than a mere chameleon that slightly adapts its characteristics to the given case. As a total phenomenon its dominant tendencies always make war a fascinating trinity -- composed of (1) primordial violence, hatred, and enmity, which are to be regarded as a blind natural force; (2) of the play of chance and probability within which the creative spirit is free to roam; and (3) of its element of subordination, as an instrument of policy, which makes it subject to reason.

The first of these three aspects mainly concerns the people; the second the commander and his army; the third the government. The passions that are to be kindled in war must already be inherent in the people; the scope which the play of courage and talent will enjoy in the realm of probability and chance depends on the particular character of the commander and the army; but the political aims are the business of government alone.

These three tendencies are like three different codes of law, deep-rooted in their subject and yet variable in their relationship to one another. A theory that ignores any one of them or seeks to fix an arbitrary relationship between them would conflict with reality to such an extent that for this reason alone it would be totally useless.

Our task therefore is to develop a theory that maintains a balance among these three tendencies, like an object suspended among three magnets.