LEIDSCHENDAM, NETHERLANDS - Former Liberian President Charles Taylor became the first head of state since World War II to be convicted by an international war crimes court, a historic verdict that sends a message that tyrants worldwide will be tracked down and brought to justice.

The warlord-turned-president was found guilty on Thursday of 11 counts of war crimes and crimes against humanity for arming Sierra Leone rebels in exchange for "blood diamonds" mined by slave laborers and smuggled across the border.

Judges at the Special Court for Sierra Leone said Taylor played a crucial role in allowing the rebels to continue a bloody rampage during that West African nation's 11-year civil war, which ended in 2002 with more than 50,000 dead. Ten years after the war ended, Sierra Leone is still struggling to rebuild.

The rebels gained international notoriety for hacking off the limbs of their victims and carving their group's initials -- RUF, for Revolutionary United Front -- into opponents and even children they kidnapped, drugged and turned into killers.

The 64-year-old Taylor will be sentenced next month after a separate hearing.

The court has no death penalty and no life sentence. Judges earlier gave eight other rebels as much as 52 years in prison.

The verdict was hailed by prosecutors, victims and rights activists as a watershed moment in efforts to end impunity for leaders responsible for atrocities.

The ruling "permanently locks in and solidifies the idea that heads of state are now accountable for what they do to their own people," said David Crane, the former prosecutor who indicted Taylor in 2003 and is now a professor of international law at Syracuse University. "This is a bell that has been rung and clearly rings throughout the world. If you are a head of state and you are killing your own people, you could be next."

'A significant milestone'

U.N. Secretary-General Ban Ki-moon hailed the judgment as "a significant milestone for international criminal justice" that "sends a strong signal to all leaders that they are and will be held accountable for their actions," U.N. deputy spokesman Eduardo del Buey said.

Despite optimism over the verdict, international efforts to prosecute leaders have been spotty at best. Slobodan Milosevic died in his cell before a verdict could be reached on charges of fomenting the Balkan wars. Moammar Gadhafi was killed by rebels last year before he could be turned over for trial. Sudanese President Omar al-Bashir is openly defying attempts to arrest him on international genocide charges.

In one success story, prosecutors at the U.N. Yugoslav war crimes tribunal are close to wrapping up their case against former Bosnian Serb leader Radovan Karadzic -- although it took more than a decade to have him arrested.

The global implications meant little to survivors of the war in Sierra Leone, who celebrated Taylor's conviction.

"I am happy that the truth has come out ... that Charles Taylor is fully and solely responsible for the crimes committed against the people of Sierra Leone," said Jusu Jarka, whose arms were both hacked off by rebels in 1999 and who now runs a support group for fellow amputees.

Crowds that gathered to watch the verdict live on television in the Sierra Leone capital, Freetown, sighed with relief when the conviction was announced. Some carried posters that exposed still-simmering anger. "Shame on you, Charles Taylor. Give us your diamonds before going to prison," one read.

Difficulties of prosecution

Prosecuting Taylor proved how hard it is to bring leaders to justice. He fled into exile in Nigeria after being indicted in 2003 and wasn't arrested for three years. And while the Sierra Leone court is based in that country's capital, Taylor's trial was staged in the Netherlands for fear it could destabilize the region.

There was no clear paper trail linking Taylor to rebels, and the three-judge panel wound up convicting him of aiding and abetting the fighters. He was cleared of direct command responsibility over the rebels.

Taylor, impeccably dressed as usual in suit and tie, said nothing in court and showed no emotion as the verdict was read.

There was emotion enough during the five-year trial as 91 prosecution witnesses outlined the horrors of Sierra Leone's war, many of them describing murders, mutilations, torture and acts of cannibalism by rebels and the children they turned into merciless killers.

Taylor insisted he was an innocent victim of neocolonialism and a political process aimed at preventing him from returning to power in Liberia. In seven months of testimony in his own defense, he cast himself as a peacemaker and statesman in West Africa.

Crane -- a vocal supporter of efforts to hold leaders accountable -- concedes that while war crimes tribunals are independent, they are hard to separate from geopolitical realities.

Syrian President Bashar Assad's regime is widely accused of atrocities as it battles to put down a popular revolt, and yet the prospect that he or any of his generals will be indicted anytime soon appears remote.

The International Criminal Court has indicted al-Bashir for genocide in Darfur, Sudan, but he has openly defied an international arrest warrant.

Most likely the next former leader to face justice will be former Ivory Coast President Laurent Gbagbo, who is jailed in The Hague on charges of attacking political opponents as he attempted to cling to power following elections last year.