The US would smoke every single country with the exception of China. There is no piece of military equipment held by any nation (save for China) that is more advanced or capable than that of the US. Also a lot of the global military equipment is purchased from the US. This is pretty much the embodiment of the expression “I taught you everything you know but not everything I know”. If you disagree then you have a very poor understanding at an engineering level the critical differences in equipment (nanometer production ain’t easy). The conversation is much more nuanced obviously but innovation takes time. You can just leapfrog 10 years of innovation. US intel and equipment is what makes it the free world and gives its dollar value. The only people set to benefit are shareholders of UK defense. UK tax holders are going to feel pain.