Semen Kryvonos, 42, faces one of the hardest jobs in a country at war: fighting an internal enemy. As director of Ukraine’s National Anti-Corruption Bureau, he is charged with rooting out the corruption that threatens both the war effort and Kyiv’s international standing. 

Appointed amid Russia’s full-scale invasion and declining public trust in the institution, Kryvonos quickly reorganized NABU, expanded its staff and oversaw its first independent international audit. He has already overseen one of Ukraine’s biggest corruption scandals, implicating senior officials and close allies of President Volodymyr Zelenskyy. 

The scandal landed at a moment when Ukraine’s Western backers are scrutinizing Kyiv’s governance more closely than at any point since the invasion. Even as NABU detectives pursued top-level cases this summer, MPs tried to strip the bureau of its independence, a decision that was quickly reversed in the face of street protests and EU pressure. When NABU published its findings in November, Zelenskyy fired two ministers, ordered an audit of all state companies and ultimately dismissed his powerful chief of staff Andriy Yermak. Critics worried the probe could weaken Ukraine at a sensitive moment, but Kryvonos argues the country shows anti-corruption efforts are functioning despite the war.

Check out the full 10 to Watch list, the POLITICO 28: Class of 2026, and read the Letter from the Editors for an explanation of the thinking behind the ranking.