The US Navy certainly makes all others look like child's play, but considering the ASBM. Americas navy has been rendered useless in the face of modern technology. mutli billion dollar machines are now only effective against those who can't produce this.
Of course, when it comes to world powers like Russia, China and the US, I highly doubt any of these nations would be able to effectively invade the other. It would all come down to ICBMs, hacking and other forms of solitary warfare. Which would be MAD. Both the US and China can shoot down satellites, and I'm willing to bet those would be the first targets in war between the two, so who knows? But it would be a nightmare on both sides.