The U.S. Navy and Air Force are currently cooperating on the most expensive procurement program in the history of the Pentagon: the F-35 Joint Strike Fighter. But recent comments by Navy and Air Force leaders about plans for the aircraft that will follow the fifth-generation fighter help explain why the F-35 was doomed to failure from the start.

Discussing how a sixth-generation fighter might look, Chief of Naval Operation Admiral Jonathan Greenert not only said the new fighter need not be high speed, he also denigrated stealth as a valuable capability for fighter aircraft. Speaking in early February, Greenert stated, “You know that stealth maybe overrated. I don’t want to necessarily say that it’s over but let’s face it, if something moves fast through the air and puts out heat – I don’t care how cool the engine can be – it’s going to be detectable.” In another shot at current fighter capabilities, Secretary of the Navy Ray Mabus later declared that the F-35 would be the last manned fighter the Navy employs.

The Air Force did not take kindly to these statements, which is not surprising for a service dedicated to speed, enamored with technology, such as stealth, and whose leadership is made up of pilots—and since the Vietnam War, largely by fighter pilots. In response to Mabus’ comments on unmanned fighters, Air Force Chief of Staff Mark Welsh argued, “Having the human brain as a sensor in combat is still immensely important in our view.”

From these comments, one might be led to think that the different services have different ideas about their aviation needs.

The conceit behind joint systems development is that large quantities of one system can be built for use by multiple services, thus saving money through economies of scale. As discussed here previously, reality has a way of intruding on such plans. Because the different services have different missions, different concepts, and, as the late RAND defense analyst Carl Builder put it, different personalities, the system each service uses, even if technically the same as that of other services, will have different requirements.

The Pentagon has attempted to jointly develop a number of multiservice aircraft over the past five decades, beginning with the F-111—a program that the Navy exited before it went into production. The only jointly developed program that did go into joint production is the F-35. And as the services have attempted to adapt the program to their individual needs after the fact, the cost has skyrocketed.

Initial reports suggest that the Navy and Air Force will rightly develop separate sixth generation fighter. Different military services exist for a reason. The Pentagon should embrace that fact. In the 1970s, the Air Force developed the F-16 for fear of being saddled with the Navy’s F-14—a plane the air service loathed. The F-16 proved to be the far superior aircraft. It is easy to bemoan the redundancy of separate services procuring different fighters, but the military’s multiple air forces have served it well. And they have done so at a far lower cost than the alternative.