Up to a point. When the accusers and "witnesses" are shown to be guilty of much greater crimes, if they are granted respect and immunity, then tribunal CONVICTS itself as being a show trial or kangaroo court. Maybe not in the eyes of the law but in the eyes of all honest people and in the eyes of God.
I am curious, what is your view of Moscow show trials of 1930s?
Trying to litigate war is a mistake, it is a basic misunderstanding of what war is. War is the state of affairs that exists when a conflict is beyond litigation.
Simply stated, when rule of law no longer holds you are in a state of war, which persists until the facts on the ground have been changed sufficient to allow peacetime laws and institutions to resume.
There is a place for war-trials at the end of a conflict, but these are not normal trials, they are an extention of the war, they are required as a part of the transition from war back to peacetime law. War prisoners, for example, who are no longer a threat at the end of the war are typically released by both sides. Certain individuals that the victorious power considers a permanent threat, however, will traditionally be hanged or shot. A war-trial documents the reasons for hanging him. It is not about guilt or innocence, typically the decision to hang him is a political or military one. The trial merely establishes the "why", sometimes the real one, sometimes the pretext.
The Allies at the end of the Second World War reasoned that some members of the Nazi regime could not be allowed to go free, ever. The Nuremberg Trials documented the reasons for hanging them. It could not be about legal guilt or innocence, because as agents of the former government, everything they did was "legal". But these were war-trials, part of the transition back to peace.
The trial of Saddam is similar in nature; Saddam can never be allowed to go free, he is a danger even in exile, he is a danger even in his cell as insurgents plan attacks to free him. But his crimes, which shock the conscience of normal people, were not legal crimes under his rule, because in essence he was the law. But this is a war-trial, the decision to hang him is a military and political one, and the purpose of the trial is not to determine his "guilt", but rather to document why he must hang.
This court is trying to establish its authority over countries which had never agreed to its authority, and to exert an authority it has not won on the battlefield. It is trying to litigate a war that is 10 years in the past. But you can not litigate war, war exists precisely when conflicts have gone beyond the reach of any court, war is by its nature extra-legal. The time to deal with a Haradinaj or any of the Serb officers currently on trial is right there on the battlefield. There is a time for war-trials in the immediate aftermath of a war, as a way of closing out old business. But this war is 10 years past, and there have been far greater crimes committed that will never be tried by any earthly court. Does the Hague propose to arrest and try the Sudanese government, for example? They have the blood of millions on their hands. This guy is accused of killing 14 people during a very ugly war. Any Sudanese worth his salt will laugh at such a puny crime as this.