Australia's mainly air and naval forces should not suffer "horrible casualties" in Iraq as its representative here, Saad Al-Samarai, predicted recently, especially if the war is short. The real problems for the ground forces in Iraq, however, begin once Saddam Hussein is removed. That's when American hopes for democracy to come to Iraq will be tested. With the Iraqi dictator gone, the lid of repression will be removed. Then Iraq's abundant internal contradictions will be exposed.
Iraq was an artificial creation. Its borders were designed by the British after World War I, when the key official in London was told by a colleague: "You are flying in the face of four millennia of history if you try to draw a line around Iraq and call it a political entity. Assyria always looked to the west and east and north, and Babylonia to the south. They have never been an independent unit."
For the four previous centuries the Ottomans kept the place under harsh control, since the people were notoriously tough and fractious. That notoriety dates back to the beginning of Arab rule, when a ruthless governor was sent to restore order. The governor killed the grandson of Mohammed and his supporters, so provoking the Sunni-Shia split in the Muslim world.
Today, Iraq remains split - not only between Shias (more than half the population), and Sunnis (about a quarter), but also the Kurds who make up more than 20 per cent. But for external reasons alone the Shias and the Kurds will have no proper representation in the new Iraq. All its neighbours are Sunni except Iran, and they would fear for the stability of the region if the Shias prevailed in Iraq. Real autonomy for the Kurds would distress Iraq's northern neighbours, notably Turkey. So there would be two strikes against democracy at the outset in Iraq.
Regime change in Iraq always raises democratic hopes, which are then extinguished. When the British had the mandate for Iraq in the 1920s they soon faced rebellion, first in the Sunni heartland and then from Shias anxious for autonomy. Months of anarchy ended only after strenuous efforts, bombing by the Royal Air Force and reinforcements from India.
When the royal family was murdered in 1958, coup followed coup: efforts for freedom of one sort or another were invariably crushed. Some of the ugliest scenes accompanied the 1963 coup led by the Ba'ath Party. The Ba'athists were overthrown, but returned violently in 1968, and have remained in power since then.
To replace Hussein, some favoured Shia general may be found, or one of the squabbling politicians-in-exile. But none will have legitimacy in local eyes, and those who have the job first are not likely to last long in it. The man to emerge as leader will come from the central Sunni heartland, and will be tough. Hussein's eventual successor might well have ties of kinship to him: Iraqis, and the Sunni Arabs in particular, are intensely clannish and have an extraordinarily high incidence of marriage between first cousins. He could in a sense be a Hussein clone.
At least initially, human rights in Iraq will improve when Hussein goes. The regime has made its own survival its top priority. For decades, those citizens who do not flee choose between toeing the line or suffering the consequences. These consequences are extreme and are enforced in an atmosphere of fear. Amnesty International's reports on torture in Iraq make horrific reading.
Systematic violation of human rights means few families are without some direct vile experience. To change the situation, the regime must be decapitated: Hussein, his clan, the repressive security apparatus and the Ba'ath Party must all go. But how thorough must this decapitation be? The Ba'ath Party has more than a million supporters; many might switch allegiance to a new president, but the party has a hard loyal core of 30,000 full members. Perhaps 10 times that number of Iraqis would feel they have so committed themselves to the regime and its excesses, sometimes for many years, that they are in the gun.
Getting rid of Hussein means confronting a large number for whom what is at stake is literally a matter of life and death. Waiting in the wings are those with terrible grudges against Iraq's abusers of human rights - and some of them live right next door. Many have had daughters raped or sons mutilated while in detention; many have themselves spent months detained without trial due to some denunciation or imagined disloyalty, crammed in cells in constant physical contact with other innocents before being allowed back home. For them, payback time approaches.
Who will oversee this coming mother of all messes? It's unlikely to be the UN. The international community, after all, has no stomach for invasion, let alone possibly years of subsequent crackdown. The invaders and their allies must do it.
Until Hussein goes, his people will defend him, and Iraqis are resourceful as well as tough. The first question as he goes is how to decapitate the leadership - how many to kill, how many to jail. New questions will arise daily, of legitimacy, of policing, in a situation of revenge killings, armed resistance and terrorism. With Iraq risking fracture, the coalition of the willing that entered may find it is in for a much longer and murkier haul than expected.
Its hope will be to exit quickly, leaving Iraq in good order. The peacekeepers' role could be thankless, dangerous and open-ended.