The walls of Kreshnik Spahiu's office in the Albanian capital bear the names of towns far beyond the borders of this Adriatic state, in modern-day Greece, Macedonia, Montenegro and Serbia.

The United States has warned leaders in NATO ally Albania in no uncertain terms to stop stoking nationalism in the run-up to an election because they risk destabilizing the region.

Spahiu's strain of hardline nationalism was once confined to the margins, but a sense of national awakening has sharpened with the 100th anniversary of Albanian independence last year and a 2008 ...