The "latest evolution of warfare" noted above:

Making America's challenge still more daunting is a major shift in war-fighting technology toward cheap, unmanned aerial vehicles. The United States and its allies in the Persian Gulf have been forced to use expensive, advanced air-defense systems"such as Patriot PAC-3 missiles that each cost millions of dollars and have a long production cycle"to shoot down Iranian drones that can be swiftly assembled for about $30,000.

Unfortunately, the Trump administration has failed to learn from the war in Ukraine. Iran has learned to mass-produce cheap drones"ones that the Russians first imported and now produce themselves. In other words, their effectiveness had been tested, and their existence was widely known. But that seemed to make no difference to U.S. planners. Perhaps in the arrogant belief that a war with Iran would quickly end in a decisive victory, the Pentagon did not have cost-effective systems ready to intercept these weapons. Neither did the Gulf countries that have counted on American weaponry for their self-defense.

"If the United States appears less powerful and less reliable than it once was and is running through munitions faster than it can produce them, many more countries will follow Ukraine's example. The Pentagon is belatedly ramping up its efforts to develop less expensive self-guided weapons. But those initiatives so far seem inadequate to address the problem that the war with Iran has revealed: a gap between America's military needs and what it is capable of manufacturing quickly and cheaply."