The Swiss... that army knife will stop anyone!

Honestly though, the US clearly has superiority in terms of destructive capability. The PRC may have a lot of men, but these days - manpower isn't everything. (I realise I may be biased somewhat here - considering I plan to join etc.) I do think the UK still has the best trained army - partly due to the training, and partly due to being pretty much continually involved in some kind of military action or other for gods know how long.