Stephen Rapp, the new U.S. ambassador at large for war crimes, knows what it feels like to be victimized. As a 21-year-old congressional intern, Rapp was kidnapped by three men, pistol-whipped, had a gun barrel shoved in his mouth, and then was thrown into the trunk of his 1961 Chevrolet. His captors took the car on a 4 1/2-hour crime spree from Washington to Alexandria, Va., before abandoning it south of the Pentagon. Rapp was released the next morning after a passerby heard him screaming for help. The ordeal has served as a touchstone for Rapp, now 60, who was sworn in last month as the State Department's point man on war crimes. The Harvard graduate has spent much of his career pursuing violent criminals, initially as a federal prosecutor in Iowa. During the past decade, Rapp has served as a U.N. prosecutor for Rwanda and Sierra Leone, where he has tried some of the world's most violent alleged mass murderers, including former Liberian president Charles Taylor. 'I see myself as a champion of those folks,' said Rapp, recalling the thousands of Sierra Leonean civilians who were raped, mutilated and killed by the country's ruthless rebel Revolutionary United Front (RUF) during a decade-long conflict that ended in 2002. In February, Rapp became the first international prosecutor to secure war crimes convictions for perpetrators of rape and sexual enslavement, a practice that led to the forced marriage of thousands of rural girls and women to RUF combatants. In his new job, Rapp is hoping to fix Americans' attention more sharply on similar crimes around the world, particular in African conflict zones such as Congo, Guinea and Kenya. He also has placed crimes against women -- a priority of Secretary of State Hillary Rodham Clinton -- at the center of his work. 'The United States has been a leader in international justice, and we need to reassert that leadership,' said Rapp, who oversees an office of 11 lawyers, diplomats and support staffers. 'The primary way that we do it is to press for accountability at the national level, at the level closest to where the crimes were committed.' Rapp's mission has been aided by a president who has vowed to abandon the most controversial practices of the Bush administration, including the use of harsh interrogation methods and secret CIA-run detention centers. But his efforts continue to be dogged by allegations that the United States adheres to a double standard in which Americans, Israelis and other crucial U.S. allies have been shielded from prosecution by international courts. Last month, a senior Sri Lankan diplomat countered a request by Rapp to investigate war crimes by the Sri Lankan military, which allegedly killed thousands of civilians in an offensive against the country's separatist insurgency. 'We're following your lead. We believe in eliminating these terroristic threats and resolving these issues once and for all,' Rapp said the official told him. Fabienne Hara, the New York representative of International Crisis Group, said that Rapp's calls for a war crimes investigation are welcome but that the United States has not lived up to its commitment to stop violence as it unfolds. Its response to war crimes in three of the most serious conflict zones of the past two years, Congo, Sri Lanka and Gaza, consists of pressing for 'accountability after the crisis rather than stopping or preventing the crisis.' Rapp said the United States has been actively seeking to put out simmering conflicts before they explode, citing cases such as Darfur, Sudan, where Washington is using carrots and sticks to dissuade the government from abusing its people. Rapp said holding perpetrators to account for election violence in 2007 could help stave off even worse violence in the country's 2012 elections. Former secretary of state Madeleine Albright formed the war crimes office in 1997 to lend U.S. support to U.N.-backed war crimes courts in Yugoslavia and Rwanda. But the office's mission changed during the Bush administration, when it helped defend U.S. counterterrorism policy and secured foreign countries willing to receive detainees held at Guantanamo Bay, Cuba. 'It was a radical reversal,' said David Scheffer, the first U.S. ambassador at large for war crimes. It changed the office's mission from 'one of going out there and advancing the agenda of international justice to one of trying to shield the U.S. from justice inquiries.' Clint Williamson, a career civil service official who headed the war crimes office under then-Secretary of State Condoleezza Rice and during the first several months of the Obama administration, said he quietly shifted the office's focus back to its traditional business of promoting accountability for war crimes. But he said he was unable to persuade the Bush administration to get his office out of the business of handling Guantanamo Bay detainees. The Obama administration, acting on his request, took the war crimes office out of the detainee business in May, Williamson said. Williamson said Rapp's extensive experience in Africa overseeing U.N. war crimes investigations would help bolster the office's image, particularly at a time when the International Criminal Court (ICC) in The Hague is pursuing numerous war crimes prosecutions in the region. 'I've known Stephen for a long time,' he said. 'I told (Secretary) Clinton that if I could handpick my own successor, he is probably the one I would have chosen.' Rapp concedes that he has confronted skepticism from foreign audiences that contend that the United States cannot build credibility as long as it shields its troops and its allies from international accountability for the same kinds of actions for which it demands the prosecution of others. The United States has vigorously opposed a recommendation by Richard Goldstone, a South African jurist who headed a U.N. fact-finding mission looking into war crimes in the Gaza Strip, that the U.N. Security Council consider approving an international war crimes prosecution of Israeli troops and Palestinian militants if they did not conduct a credible inquiry on their own. 'I'm a good friend of Richard Goldstone; he was on the committee that appointed me to the Sierra Leone job,' Rapp said. But he added that any discussion of international prosecution 'is jumping the gun.' Rapp said he has pressed the Israelis and Palestinians to conduct their own investigations. He said a group of parliamentarians from about 70 countries told him last month that the United States' refusal to seek ratification of the ICC treaty -- which would expose U.S. nationals to possible prosecution -- creates a double standard. Rapp said that the United States' approach to the Hague-based criminal court is under 'active review' and that the Obama administration is exploring the prospect of being 'more actively engaged with the (the court) in places where it's consistent with our interests and policies.' In a sign of a shift, Rapp led a delegation of U.S. diplomats to a conference of the ICC's member governments in The Hague, the first time the United States has done so in nearly eight years. But the U.S. review, he added, 'will not result in a decision to submit the ICC treaty to the Senate in the near future.' Rapp also reiterated the Bush administration's argument that 'no legitimately motivated international prosecutor in the ICC or elsewhere should ever have legitimate cause to take a case against an American citizen.' 'We have a very good justice system that has a record of holding people to account, at the highest level,' Rapp said. 