Having watched numerous bits of military procurement from the sidelines via reporting over the decades...the problem comes down to the people running the progra

Having watched numerous bits of military procurement from the sidelines via reporting over the decades...the problem comes down to the people running the program having no idea WTF they want, and only knowing what they DON'T want after they've received a prototype that fits the constraints they've laid out and realize that no, what they asked for was dumb and not usable or is literally impossible to make with the state of the art. Go through a few iterations of refinement for them to get their heads out of their asses with something expensive like a new fighter and it's easy to see how the cost has ballooned. However, if they keep funding the program they can work through the right tradeoffs to end up with something that works better than what was before, while maybe not quite hitting the marks that were planned on at the outset. It just costs $billions of development and years to work through. Fortunately, Americans are willing to spend hilarious amounts of money on our weapons systems so we can get something useful at the end of the program. Occasionally we pull the plug because the program was so ill-thought-out that there's no way to salvage it, like with the Zumwalt.