With its winding lanes and stands of cherry trees, Camp Zama, a U.S. Army base twenty-five miles outside Tokyo, feels more like a meditation retreat than a military facility. Until it was seized by the First Cavalry in September 1945, Zama was the West Point of the Imperial Japanese Army. Through the decades, the forest has been pushed back to accommodate a larger airstrip, a fire has taken out the old Japanese barracks, and most of the camp’s remaining structures have been replaced with drab buildings set discreetly into the lush green prettiness. One structure from the Imperial era remains:…