Army Gen. Austin “Scott” Miller, who has overseen the war effort for nearly three years, will relinquish responsibility in a ceremony at the top U.S. military headquarters. President Biden said last week that the military withdrawal he ordered will be complete Aug. 31, but Miller’s departure is among the only pieces left. Virtually all other troops, contractors and equipment already have exited, defense officials said on the condition of anonymity because of the issue’s sensitivity. Miller will depart Afghanistan as the war’s longest-serving senior U.S. officer. A former commander of the elite Delta Force, he oversaw a tumultuous period that included the Trump administration’s 2020 deal with the Taliban that set the stage for withdrawal, and the final call by Biden in April to remove all troops. Marine Gen. Kenneth “Frank” McKenzie, the chief of U.S. Central Command, arrived in Kabul on Monday morning to assume command of the remaining mission. He is expected to oversee the small-scale operation from his headquarters in Tampa, with a two-star Navy SEAL, Rear Adm. Peter Vasely, leading about 650 troops tasked with protecting the U.S. Embassy. McKenzie told reporters traveling with him that he believes the Taliban are pursuing a “military victory” over the Afghan government, citing its recent battlefield victories in numerous parts of the country and the threat it poses to several provincial capitals. But he predicted the militants will encounter significant resistance in Kabul, noting how much larger and more complex the city of 6 million people and its defenses are now than when the Taliban ruled it in the 1990s.