Monday's dual developments of two accused international criminals showed the differences -- and difficulties -- of America's unilateral approach to adjudicating war crimes.

In Serbia, officials announced the arrest of Radovan Karadzic, who had eluded NATO authorities for 13 years. Nearly unrecognizable from his days wearing military fatigues and sporting a shock of gray hair, he had been hiding in plain sight in Belgrade, having grown a long white beard to match his now-white hair.

But if Karadzic's look was now forgettable, his alleged crimes aren't: Indicted in July 1995 by the International Criminal Tribunal for the former Yugoslavia, he is accused of genocide, crimes against humanity, violations of the laws or customs of war and grave breaches of the Geneva Conventions of 1949.

His infamous, sadistic reign as president of the Serbian Democratic Party put him at the center of the Balkan wars of the 1990s, including the siege of Srebrenica and the subsequent slaughter of 8,000 men and boys.

The court and The Hague had taken heat for being all talk and no action; recall its interminable trial of former Yugoslav leader Slobodan Milosevic, who finally died of natural causes while awaiting a verdict. Meanwhile Karadzic remained at large, as did his alleged accomplice, Gen. Ratko Mladic, who faces many of the same charges.

But all that talk now gives the action great global legitimacy. The International Criminal Tribunal has a worldwide mandate to bring those accused of crimes against humanity to justice.

Monday also marked the beginning of the first U.S. military commission since World War II, as the first Guantanamo Bay detainee, Salim Ahmed Hamdan, came to trial. The government seems to have a good case, as he is the former driver for Osama bin Laden and is accused of being a bodyguard and arms dealer for Al-Qaida.

But how it got that information is suspect. And not just to standards of the world community, but to the military judge, who threw out some evidence after ruling it was obtained under "highly coercive" conditions during Hamdan's incarceration and interrogation in Afghanistan.

Both men may be equally guilty. But the burden of proof -- and the degree of difficulty -- is much higher in the case of Hamdan, showing once again how America is strengthened, not weakened, by working within the framework of a well-established international legal system.