Unfinished business in Bosnia.

The European Union will have a full agenda when it replaces NATO as the head of the peacekeeping mission to Bosnia-Herzegovina, according to senior commanders and diplomats.

"The environment remains fragile," said Maj. Gen. Virgil Packett, commander of the NATO stabilization force.

The EU will by year's end deploy an initial force of 7,000 troops, down 1,000 from the current number. Their mandate is to maintain a safe environment, train Bosnia's armed forces and support the rule of law. The devil of this mission, like many others, is in the details.

One main obstacle to a stable region is the presence of indicted war criminals and their network of supporters. Topping the list is Radovan Karadzic the founding member and president of the Serbian Democratic Party in the former Socialist Republic of Bosnia and Herzegovina. He has been indicted for genocide, crimes against humanity and violations of the laws of war by the International War Crimes Tribunal for actions taken against Muslims in the 1990s.

U.S. officials said Karadzic heads a network of resistance that provides an alternative for the disgruntled Serb masses.

"He is, perhaps, holding the country hostage," Packett told the House Armed Services Committee in July. "The people of Bosnia-Herzegovina have to choose between Karadzic and Europe," he said. "I think they're choosing Europe."

The strategy of NATO and the embryonic domestic defense force has been to attack Karadzic's supporters, seizing assets, shutting down media outlets owned by family members, isolating organizers through travel restrictions and closing businesses acting as fronts for resistance.

"We're hearing them squeal a little bit," Packett said, but added that his opponents were mobile and well informed. "Karadzic and his network are clearly a world-class counter intelligence piece ... This network is so comprehensive and inculcated with the population."

This underground web of sympathizers compromises operations, he added, since targets know when soldiers prepare to launch a strike. "They say, 'We don't know where they're going, but they're moving.' Everybody has a cell phone."

Karadzic is only one of 17 wanted fugitives. These remaining indicted war criminals include leaders who helped promote the violent conflict that inspired the intervention in 1995, including Rato Mladic, who held the rank of general in the Bosnian Serb armed forces and Ante Gotovina, the Croat commander who was complicit in the murder of scores of Serbs and the forced deportation of 200,000 others.

The issue has become a main sticking point for European nations. This year, during an EU conference in Istanbul, the failure to arrest these wanted men was cited as the chief reason for not including Bosnia-Herzegovina in the Partnership for Peace program. That program would have increased military collaboration and training with NATO, and served as a positive step towards inclusion in the European Union.

"We need the Partnership for Peace program for economic reasons," noted Igor Davidovic, the ambassador of Bosnia-Herzegovina to the United States. "One step closer to NATO means one step closer to the European community."

Mirza Kusljugic, Bosnia-Herzegovina's ambassador to the United Nations, told the committee that local authorities would arrest the "superior strategists of the criminal enterprises" by the end of the year.

Another major piece of unfinished business is the wide minefields that carpet the country. Mines, Packett pointed out, threaten more than 1,000 square miles-half the size of Rhode Island. "At the current rate of de-mining, it will take 75 years to complete," he said. Tourism, trade and agriculture all suffer from the hidden presence of mines.

Bosnia-Herzegovina is also a flashpoint of the global efforts against terrorism and international criminal cartels. Its loose borders and weak internal security permit transit points for drugs, weapons and illicit cash, U.S. officials said. Muslim extremists operate fundraising activities to support al-Qaeda. Still, the direct danger to international forces is not seen as large.

"In general the threat of terrorist influence in Bosnia is low," said Maj. Gen. James Darden, deputy director for plans and policy for U.S. European Command. "Most reporting of terrorist training today is more related to a continued perception that war can break out at any time, especially as the international community reduces its physical footprint in the country, and that the population must be ready to defend itself along ethnic lines."

Indeed, the largest challenge facing EU forces is the changing mentality of people who've experienced centuries of mistrust and conflict. While signs of normalcy are increasing, tensions remain.

"While NATO and U.S. efforts have spurred peaceful cohabitation, there is no overt feeling of reconciliation," Packett said. "Latent distrust, even hatred, remains, but the amount is difficult to quantify."