A U.S. Air Force squadron flying F-35 stealth fighters traveled to Hawaii in late January 2020 for the first-ever exercise combining the single-engine F-35s with twin-engine F-22 stealth fighters from the island state’s resident Air National Guard fighter wing.

Exercise Pacific Raptor took place at Joint Base Pearl Harbor-Hickam and involved 600 airmen from the Hawaii Air National Guard’s 199th Fighter Squadron and its associated active-duty unit the 19th Fighter Squadrons, as well as the 63rd Fighter Squadron from Luke Air Force Base in Arizona and the Alaska-based 18th Aggressor Squadron.

The 18th Aggressor Squadron flies F-16s to simulate enemy planes during war games. Hawaii-based KC-135 tankers and air-defense coordinators supported the Pacific Raptor exercise, which concluded on Feb. 7, 2020.

Similar exercises in the coming years could feature even more sophisticated mock adversaries. The Air Force is trying to stand up its first aggressor squadron flying stealth fighters.

"The most exciting and beneficial parts of Pacific Raptor were the ability to integrate with the F-22 and train to an advanced threat, replicated by F-16s," said Maj. Justin Miller, a 63rd Fighter Squadron pilot and one of the exercise planners.

The F-35 and F-22 could face an even more advanced threat in future war games, if the Air Force can convince Congress to let it proceed with plans to convert early-model F-35s into aggressor planes.

The Air Force in May 2019 announced it would re-establish a defunct F-15 aggressor squadron to operate the roleplaying F-35s. The service in 2014 shuttered the 65th Aggressor Squadron as a cost-saving measure.

The 65th Aggressor Squadron in its new form would operate nine early-model F-35A stealth fighters that the Air Force considers unsuitable for combat. The “red air” F-35s would help the Air Force to copy the tactics of Russian and Chinese squadrons respectively flying Su-57 and J-20 stealth fighters.

The unit would require 194 military personnel and 37 contract personnel plus an additional 60,000 square feet of facilities and 300,000 square feet of ramp space at Nellis Air Force Base in California, said Col. Travolis Simmons, commander of the 57th Adversary Tactics Group.

The 65th Aggressor Squadron’s F-35s, which currently are with a training unit at Eglin Air Force in Florida, may be some of the least capable of the Air Force’s roughly 200 F-35s, but they still represent a major upgrade for the service’s aggressor force.

“The F-35's ability to play the bad guy will surpass that of any aircraft ever tasked with the mission before,” The War Zone editor Tyler Rogoway wrote.

The aircraft is uniquely suited to replicate a wide range of threats with unprecedented high fidelity. I have talked with sources about this in the past and they have noted that the F-35's software alone should be able to be manipulated to replicate the sensor, sensor fusion, electronic warfare and communications capabilities of adversary threats.

In other words, applications could be designed to limit various aspects of the F-35's capabilities—and enhance others synthetically via data-link—to better mirror that of the aircraft it is masquerading as. In addition, it can be equipped with bolt-on radar reflectors that may be able to be manipulated to better replicate certain radar signatures of enemy aircraft, including those that aren't even stealthy at all.

Once the 65th Aggressor Squadron stands up, the Air Force will have three dedicated red-air units. The 64th Aggressor Squadron flies F-16s from Nellis.

But Congress has delayed the Air Force’s plan to establish an F-35 aggressor unit. The 2020 defense policy bill prohibits the Air Force from transferring F-35s to the adversary air role until Air Force chief of staff Gen. David Goldfein submits a report to Congress detailing the service’s plan for modernizing its existing aggressor fleet.

So for now, F-16s are among the most capable adversaries that F-35 and F-22 squadrons can hope to face in mock combat.

David Axe serves as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix, War Is Boring and Machete Squad.