America’s two most senior military leaders are expected to address on Wednesday the completion of the U.S.-led evacuation effort at Kabul airport and the end of America’s 20-year war in Afghanistan. Both Secretary of Defense Lloyd Austin and Gen. Mark Milley, chairman of the Joint Chiefs of Staff, served combat tours in Afghanistan during their long military careers. “As we look back as a nation on two decades of combat and struggle in Afghanistan, I hope that we will do so with as much thoughtfulness and humility as we can muster,” Mr. Austin said in a statement released after the...