With Space anyone can try to get there and prove their technology. There's even an event held once a year out in Nevada where you can show up with whatever rock

With Space anyone can try to get there and prove their technology. There's even an event held once a year out in Nevada where you can show up with whatever rocket you want and try for it. War fighting isn't the same, you can't prove your plane is good in combat on your own. You need a war and a side willing and able to fly it in combat.