Answer
German. Sebastian Kehl, a retired German footballer and current director of player personnel and development at Borussia Dortmund, was born in Fulda, Germany, on February 13, 1980. During his playing career, which spanned from 1998 to 2015, Kehl made significant contributions to German football domestically and internationally. His nationality is deeply rooted in his German heritage and the impact he made on the sport within the country.