President Biden will address the graduating class of cadets at the U.S. Military Academy, West Point, on Saturday, delivering a commencement speech at a moment of military upheaval abroad, university protests at home and a looming White House rematch with former President Donald J. Trump.

Mr. Biden is expected to congratulate the Army’s newest officers, describe the global challenges facing the military and remind the cadets of the oath they took — not to the president, but to the…