It’s this: https://en.m.wikipedia.org/wiki/Millennium_Challenge_2002
Basically a US war gaming exercise against Iran. The US did horribly, to the point that they hobbled the opfor so that the bluefor could win. The marine general who commanded the opfor did a bunch of asymmetrical warfare stuff that the Iranians might do and just clobbered the conventional forces.
The Atlantic, surprise surprise, is in full consent manufacture mode. It’s so on the nose you can practically see the talking points emails…