Ukraine’s surprise advance into Russia a dilemma for Biden BBC.com‘Completely undefended’: Nick Paton Walsh reports from Russian border point CNNOne week in Kursk: Maps show Ukraine offensive as Russia builds trenches after attack USA TODAYUkraine gambled on an incursion deep into Russian territory. The bold move changed the battlefield The Associated PressUkraine offensive in Russia expands beyond Kursk region, soldiers say The Washington Post