The five panel tribunal unanimously decided that Bush and Blair committed genocide and crimes against peace and humanity when they invaded Iraq in 2003 in blatant violation of international law.
The judges ruled that war against Iraq by both the former heads of states was a flagrant abuse of law, act of aggression which amounted to a mass murder of the Iraqi people.
In their verdict, the judges said that the United States, under the leadership of Bush, forged documents to claim that Iraq had weapons of mass destruction.
They further said the findings of the tribunal be made available to members of the Rome Statute and the names of Bush and Blair be entered into a war crimes register.
Both Bush and Blair repeatedly said the so-called war against terror was targeted at terrorists.
Lawyers and human rights activists present here say the verdict by the tribunal is a landmark decision. And the Kuala Lumpur War Crimes Foundation said it would lobby the International Criminal Court to charge former US president George Bush and Former British prime minister Tony Blair for war crimes.