Isn't that that somewhat like the future is a highway with an infinite number of lanes? Each lane represents a different future. You can change lanes as many times as you like, but you can't see far enough ahead to view the destination.Well yes the US had a lot of cash but a large amount of that went into a host of projects that went nowhere.
Or in this case each lane represents a different weapons system, but you can't see far enough ahead to know if the result will be useful.
The difference between the US and the UK is that US could afford to drive down more lanes, knowing in advance that some of them would be dead ends but didn't know which would be the dead ends when it started.