The Trump Administration, , is deploying 3,000 troops, including fighter jets and missiles, to Saudi Arabia. This being October 2019, the irony doesn’t stop there: the weapons the Pentagon is sending to protect the Kingdom of Saudi Arabia would have difficulty defending against the kind of drone and cruise missile attacks that prompted the deployment to begin with.

The deployment includes two squadrons of fighter jets, presumably F-15 Eagles, an air expeditionary wing (roughly equivalent to a U.S. Army division headquarters), two , and a (THAAD) system.

Secretary of Defense Mark Esper at a press conference:

“There are things we pick up, if you will, through intelligence that we thought it was important to continue to deploy forces to deter and defend, and to send the message to the Iranians: do not strike another sovereign state, do not threaten American interests, American forces, or we will respond,” he said. “I’ve said time and time again, do not mistake our restraint for weakness. If you will, you will regret that.”

The Pentagon is sending the forces in response to a September 15th on Saudi Arabia’s oil facilities. The attack temporarily took out five percent of the world’s oil production. The Pentagon also believes that Iran is responsible—a reasonable view given recent events and the nature of the Iranian regime.

On September 14, some as-yet officially unknown perpetrators launched a complex attack on Saudi…

All that said, the authorized by the Secretary of Defense is like something out of the 1990s, when nobody had ever heard of drone strikes or cruise missiles operated by non-state actors. It’s the wrong combination of forces for addressing low-altitude threats, but it’s also true the U.S. presently has no good combination of forces for such a scenario.

You may not care, or think that maybe we shouldn’t be spending insane amounts of money to protect Saudi Arabia at all. But here is the worst part: the deployment will just endanger more American troops by placing them in harm’s way.

The September 15th strikes involved multiple drones and cruise missiles striking Abqaiq, the world’s biggest oil-processing facility, and the oil fields at Khurais. Cruise missiles by definition fly at subsonic speeds, at low altitudes to avoid enemy radars. The drones, which apparently were guided to their target by GPS waypoints, operated in a similar manner. The problem was reportedly exacerbated by Saudi Arabia’s deployment of its Patriot missile batteries facing southward, in the direction of Yemen, instead of eastward across the Persian Gulf where the attack allegedly originated.

Patriot is a good surface to air missile system, but it suffers from limitations against low-altitude threats. Basic physics means the Patriot’s radar is limited by the curvature of the earth, the radar’s height, and the height of the object it’s trying to detect. A radar 20 feet off the ground (say, a Patriot radar) trying to detect an object 200 feet off the ground (say, a cruise missile) means the radar can detect the missile at .

The Pentagon is sending two Patriot batteries to Saudi Arabia, which include just two radar systems. Total radar coverage for this vaunted deployment: just 52 miles. Of course, the U.S. could reinforce the Patriots with additional radars, but the idea that a deployment of just two batteries can meaningfully defend Saudi interests spread out over 800,000 square miles of territory is like showing up to the with a bucket of sand.

Another system being sent to KSA with limited utility is a Terminal High Altitude Area Defense (THAAD) ballistic missile defense system. As the name suggests, THAAD is only capable against ballistic missile warheads shooting down from very high altitudes on ballistic or aeroballistic trajectories. After a rocky development period, THAAD has emerged a fairly reliable system—at least in canned, scripted Pentagon testing.

The problem with the THAAD deployment is that the system is utterly incapable of engaging low-flying targets. THAAD is useful against , but they would not be useful against cruise missiles and drones. It could be that THAAD will cover the ballistic missile threat while Saudi Arabia’s Patriot batteries are redeployed against the low-flying threat.

Ironically the most useful weapons deployed to Saudi Arabia could be the F-15 Eagle. An F-15 Eagle can patrol large swathes of friendly airspace, scanning below with its APG-63(V)3 Active Electronically Scanned Array (AESA) “look down, shoot down” radar. Once it detects a cruise missile it can then shoot it down with an AMRAAM air-to-air missile. But Saudi Arabia’s airspace is vast, and cruise missiles and drones are very small. Saudi Arabia already has , all as competent as their American equivalents. Would an additional 24 American jets make any difference?

The truth is, the U.S. is about as unprepared to face low altitude threats like cruise missiles and drones as anyone else. The post-9/11 period saw U.S. air defense forces and systems stagnate, as neither Iraqi insurgents or the Taliban had an Air Force to fight. North Korea’s breakneck nuclear program put the spotlight on ballistic missile defense, but cruise missiles and drones have, for the most part, literally slipped under the radar. There’s been a new emphasis on countering these threats, but the services are responding slowly and getting distracted by shiny objects () instead of quickly developing defenses.

The biggest problem with this deployment is that it contributes so minimally to Saudi security while placing 3,000 American troops in harm’s way. The deployment smacks of security theater more than anything else, posturing that makes one person look good while placing thousands of others in range of in a potential combat zone within range of an adversary known to be hostile to the United States.

As bad as this is, it doesn’t rank as the worst foreign policy and defense decision of this month—. Can’t wait to see what November brings.