On Monday evening, President Trump presented the latest “new” strategy for Afghanistan. But the only thing distinguishing his speech from past presidents’ remarks on the war in Afghanistan was his egregious use of the sacrifice of American service members to justify expanding the United States’ military commitment. Everything else was a repeat of what has become the standard operating procedure in Washington.

What Mr. Trump’s speech actually did was shed light on the delusion that both Republican and Democratic officials and policy makers have operated under when it comes to the “war on terrorism.” For the last nearly 16 years, both parties have followed the same script, one based on false, costly assumptions that they refuse to challenge, crossing ethical boundaries without acknowledgment — all the while steadfastly refusing to learn from their mistakes and change course.

There is little clarity about whom the United States is really at war with. Successive presidents have lumped disparate and often competing militants into simplified categories — “terrorists,” “violent extremists” or just “the enemy.” Mr. Trump’s latest iteration only deepened the confusion, warning that “20 U.S.-designated foreign terrorist organizations are active in Afghanistan and Pakistan.” He gave no clue which threaten Americans, or which America’s sons and daughters will fight against when they deploy (or, more often, redeploy). He also didn’t explain whether “victory” requires that all are defeated, or some, or just one. More broadly, the question of why, according to the State Department, the number of foreign terrorist groups has grown from 28 in 2002, to 44 in 2009, to 61 today has yet to be answered.

While describing terrorist groups as a monolithic enemy, Mr. Trump also repeated a disproved belief shared by his predecessors: that terrorists require “safe havens” from which to conduct attacks, and therefore a reduction of American troops in combat zones will mean “you get hit again,” as Secretary of Defense Jim Mattis ominously warned in June. This is based on a fundamental — and inexcusable — misunderstanding about the Sept. 11 attacks, where the hijackers passed undetected through border checkpoints 33 times and enjoyed the safe havens of southern Maryland, San Diego and Oklahoma City.