The world has shown a "callous disregard" for the 70,000 people killed in Sudan's Darfur conflict, a human rights lobby group says.
Many refugees say they were attacked by Arab militias and soldiers
The New York-based Human Rights Watch singles out UN Security Council veto holders China and Russia for blocking tougher action against Sudan.
It says they are more concerned about protecting oil contracts and arms sales to Khartoum than saving lives.
HRW says the government backs Arab militias attacking black Africans.
But the Sudan authorities deny funding or arming the Janjaweed militias and blame the conflict on rebels who took up arms, claiming to be fighting for the rights of Darfur's non-Arab groups.
Some two million people have fled their homes and many report being attacked by Janjaweed militias on horses and camels, in conjunction with the Sudanese army.
Last week, UN Secretary General Kofi Annan warned that the violence in Darfur was increasing and that groups were re-arming.
In its annual report, HRW says a large UN-authorised military force is needed to protect Darfur residents, and criticises Western powers for handing the situation to the relatively inexperienced African Union.
After the 1994 genocide in Rwanda, "Darfur is making a mockery of our vows of 'never again'," said HRW executive director Kenneth Roth.
The report also says that the crimes committed in Darfur must not go unpunished, adding that the International Criminal Court should be used to prosecute those guilty and that permanent members of the Security Council "should not stand in the way of bringing the mass murderers in Darfur to justice".
HRW says that China owns a 40% share in Sudan's main oil producing field, while Russia is thought to be the main arms supplier to the Sudan government.
It says that these two permanent members of the UN Security Council threatened to use their veto in order to "water down" the threat of sanctions against the Sudan government contained in draft UN resolutions.
HRW's 527-page annual report covers the developments in human rights in more than 60 countries in the past year.
It accuses the United States of eroding human rights and losing the moral high ground following the Abu Ghraib prison abuse scandal in Iraq and the treatment of terror suspects at Guantanamo Bay.
It says that other countries have used the US-led war on terror to introduce draconian legislation.
Although improvements were noted in several African countries, such as Angola, Burundi, Liberia and Sierra Leone, the report said concerns remained about governments' commitment to protect human rights.