Barred from Britain: Shamima Begum Loses Effort to Return to U.K. in Fight for Citizenship

Shamima Begum, who as a schoolgirl left her London home to join the Islamic State in Syria in 2015, lost an effort before Britain’s Supreme Court on Friday that could have allowed her to return home to fight the removal of her citizenship.

The ruling could have far-reaching implications for other Westerners associated with the extremist group, long left to remain in detention camps in northeastern Syria.

Ms. Begum, now 21, hoped to return to Britain to appeal a 2019 decision by the British government to strip her of her citizenship, a move that could render her stateless, and successive court appeals from both sides pushed the case to the country’s top court. On Friday, the Supreme Court’s five judges unanimously dismissed her appeals.

Ms. Begum was 15 when she boarded a flight to Turkey with two friends and entered Syria to join the Islamic State. She married a Dutch fighter and had three children, all of whom have since died.

The decision to strip her of her citizenship could leave her stateless. Ms. Begum is a single nationality holder, but British authorities have argued that she could claim Bangladeshi citizenship through her mother. (Bangladeshi authorities have said they would not grant citizenship to Ms. Begum.)