JUNE 25 marks the 140th anniversary of the Battle of the Little Bighorn, otherwise known as Custer’s Last Stand, part of the 1876 counterinsurgency campaign we call the Great Sioux War. Given that the United States today is engaged in two deadly counterinsurgency wars, fighting the Taliban in Afghanistan and the Islamic State in Iraq and Syria, it is useful to study this history for what it can tell us about an adversary and ourselves. Examining the stunning drawings made in 1881 by Red Horse, a Mnicoujou warrior who fought at the Little Bighorn, provides timeless lessons about war.