International criminal law has come a long way since Nuremberg - victors' justice done by judges from the allied powers. At the Tribunal in the Hague, Milosevic will be able to object to judges from Nato countries, on the same principle that won Pinochet a new appeal hearing. His court would comprise three judges from neutral countries who may not believe all they hear from Nato press briefings.
The Hague court has so far surprised its prosecutors by rejecting a good many of UN chief war crimes prosecutor Louise Arbour's confident charges. And, to judge from the indictment unveiled this week, Milosevic and his commanders would have a shaky, but at least an arguable, defence. He is not, curiously, charged with ordering the Vukovar hospital massacre in 1991, when his army machine-gunned 260 Croatian patients, doctors and nurses into a mass grave. The compelling evidence of his guilt for that atrocity caused him to be named as a war criminal by the US State Department, which then decided he was more use at negotiating tables in Geneva and Dayton than in the dock at the Hague.
There is a lot of evidence of his complicity in the crimes of Karadzic, Mladic and Arkan, but much of it is contained in GCHQ intercepts, picked up from Cyprus, which our Foreign Office adamantly refused to hand over. Besides which, Nato cravenly declined to arrest Karadzic and Mladic (indicted as early as May 1995) because this was publicly said to be "not worth the blood of one Nato soldier". Privately, it was feared they might turn "Queen's evidence" and force the indictment of Milosevic, who was considered not only someone the West should make deals with, but legally untouchable as head of a sovereign state.
Nato bombing has changed all that, and the scoundrel's refuge of "sovereign immunity" has at last been ended - first by the proceedings against Pinochet, and now by the indictment of Milosevic. But he has been charged with ethnic cleansing this year in Kosovo, and not with earlier crimes. So his guilt will crucially depend upon evidence about the timing and the scope of "Operation Horseshoe" - the plan for ethnic cleansing that his prosecutors allege was in operation by the time - 24 March - the West commenced bombing Serbia.
The case against him hinges on allegations that Operation Horseshoe was a planned act of murderous ethnic persecution - a crime against humanity as defined by Article 7 of the Rome Statute for the International Criminal Court, endorsed in July last year by 120 nations (and opposed, ironically, by the US). It is crucial for the prosecution to prove that this operation was under way before the bombing began. Otherwise, the defendants could claim that their ethnic cleansing - about which, after that date, there can be no doubt - was an act of self-defence, a removal of potential enemies necessitated by an unlawful Nato attack on Serbian sovereignty.
A defence of this kind would require the court to rule on Nato's contention - rejected by Russia and China - that an attack on the sovereign territory of a UN member in order to end crimes against humanity is lawful, notwithstanding the lack of express sanction by the Security Council.
This is the better view of an evolving international human rights law, which has come to embody the moral imperative of combating crimes against humanity, irrespective of power games in the Security Council with its record of corrupt and irresponsible use of the superpower veto. The concept of the "crime against humanity" - a widespread and systematic deployment for political purposes of murder, torture or persecution - is becoming recognised as the legitimate basis for penetrating the shield of sovereignty which has hitherto protected the worst perpetrators. Hence the justice of arresting Pinochet, of Tanzania's courageous invasion of Uganda to remove Idi Amin and even of the US invasion of Grenada to overthrow the crazed killers of Maurice Bishop - actions hypocritic- ally condemned by relieved UN members at the time.
But the view that the UN Charter's protection for state sovereignty is absolute, save in cases of express Security Council sanction or in self-defence, is still held by some international lawyers: would the Chinese and Russian judges on the Hague tribunal be sufficiently independent to take a more progressive view?
The Greek chorus that the indictment is "political" is outrageous. It was authorised by an independent Tribunal judge, David Hunt, a justice of the New South Wales Supreme Court who (unlike most of his brethren at the Hague) has vast experience of presiding over criminal trials and is renowned for even-handedness. It is his decision that Milosevic has a case to answer which must command respect and makes arrest a legitimate war aim.
Another recent development of international law (notably by the Inter- American Court in respect of the torturers of Latin America) has been to invalidate amnesties and pardons for political and military leaders if given for crimes against humanity. So there can be no question of Milosevic leaving Kosovo as General Cedras left Haiti, with Swiss bank account intact and a luxury home awaiting in Panama. His surrender for trial must be made a condition of any peace agreement.
If Milosevic has any courage it's a condition from which he will not shrink, precisely because of the fairness he can expect and the real opportunity of acquittal. But courtroom courage is not a quality that men of his ilk normally display. Pinochet cowers in Surrey rather than taking the next plane to Spain to face down his few remaining charges. Idi Amin dares not venture from Saudi Arabia, or Mengistu from the bosom of Mugabe. Milosevic needs a protector who will not disgorge him under pressure of UN sanctions - so Baghdad beckons. He may find it less comfortable than the cell awaiting him in the Hague or (if convicted) in Finland for his life sentence.
Churchill opposed Nuremberg: he wanted the Nazi leaders shot on sight, but was overruled by Truman, who believed in "the beneficent power of law and the wisdom of the judges", and Stalin, who believed the opposite but liked show trials where everyone was shot at the end. To his great surprise, Admiral Doenitz (acting head of the German state at its surrender, and so the only precedent for Milosevic) was actually acquitted of the serious charges (relating to his U-boat orders) when Chester Nimitz, commander of the US Fifth Fleet, came forward to admit to giving similar directives.
International criminal justice can be fair, and the conviction of Slobodan Milosevic can by no means be regarded as a foregone conclusion. For that reason, Nato should no longer be bombing him to the conference table, but to the dock.
Geoffrey Robertson QC is author of "The Justice Game" and of "Crimes Against Humanity - the Struggle for Global Justice", published by Allen Lane next month.