One of the toughest tasks facing Viktor Yushchenko as Ukraine's new president likely will be overhauling the State Security Service, the KGB successor agency alleged to have been involved in an array of devious and deadly activities.
The cases of other Soviet-bloc countries show that success or failure could determine how well democracy takes root in Ukraine -- but the issue is complicated by indications that security forces played a role in averting a crackdown on Yushchenko's "Orange Revolution."
Since the 38,000-strong SBU was formed in 1991 after independence from the Soviet Union, it is alleged to have been connected to organized crime, shady weapons deals and the deaths of several prominent opposition politicians and journalists.
It is suspected of involvement in the September dioxin poisoning of Yushchenko, which took him off the campaign trail for weeks and left his face badly disfigured. He fell ill from the poisoning within hours after having dinner with top SBU officials.
Throughout the region, security agency reform has been a mixed bag of results.
The Czech Republic -- now a successful market-driven democracy -- dissolved its former communist secret police, the STB, after the 1989 Velvet Revolution and barred former high-ranking communists and secret police agents from holding public office.
By contrast, Belarus, whose President Alexander Lukashenko is widely considered Europe's last dictator, has retained unchanged the structure -- and the name -- of the feared Soviet-era security agency, the KGB.
In Russia, the KGB was broken up into several agencies, but the main successor organization, the FSB, retains much of the clout of its predecessor. President Vladimir Putin, himself a former KGB officer, has brought into government many high-ranking former security officials.
Ukraine's security agency is highly factionalized, with internal clans loyal to different political camps. Which one was dominant came under question the day after the Nov. 21 election, when demonstrators jammed Kiev to protest voting fraud after Yushchenko was declared the loser.