Show of the week: Frontline: Obama’s War

Gripping, graphic footage of fierce combat in Afghanistan’s Helmand province—in which a young Marine is fatally wounded by Taliban fighters—opens this probing on-the-scene assessment of President Obama’s hotly debated counterinsurgency strategy. Traveling across the country with troops, correspondent Martin Smith finds “a huge exercise in nation-building” being carried out by rank-and-file soldiers. Meanwhile, an expert tells Frontline, “we’re not really sure what to do” across the border in Pakistan. The report features an interview with top Afghanistan commander Gen. Stanley McChrystal. Tuesday, Oct. 13, at 9 p.m., PBS; check local listings