Poland has elected Karol Nawrocki, a conservative historian and staunch nationalist, as its next president in a closely watched vote that signals a resurgence of right-wing populism in the heart of Europe.

Karol Nawrocki, the conservative Trump-backed candidate in Poland's runoff election, has narrowly won the presidential race. Charles Kupchan, a senior fellow at the Council on Foreign Relations, breaks down how the election results may affect NATO and Poland's relationship with the European Union.

Polish nationalist candidate Karol Nawrocki won the second round of the country's presidential election with 50.89% of the votes, the electoral commission said on Monday, in a blow to the reform agenda of the pro-European government.