Russia shouts; China whispers
Russia makes a lot of noise because it is actually quite weak. Its economy is in bad shape, not least because it's a kleptocracy crippled by the wholesale theft of assets by KGB thugs and their fellow criminals after the fall of the wall, and also because it spends proportionately far too much on weaponry, plus it is badly affected by western sanctions imposed for serious criminality. (For one thing, nerve agent attacks on foreign soil are far beyond acceptable behaviour.) Plus little Vlad The Emailer, riding the tiger, knows that when he falls or is pushed off he won't survive a day, is therefore desperate to maintain his position, which he thinks he can do by childish shirtless stunts and lots of chest-beating. Russia shouts because it is just not that powerful.
China, on the other hand, quietly builds upon its enormous economic strength. Although Xi has made some bad mistakes in accelerating his military adventurism, on the whole China continues to whisper and do diplomacy while becoming stronger every day. NSA and GCHQ and the other Five Eyes operators have been so busy spying on my browsing habits—are you bored to death yet?—that they have, in their largely pointless attempts at active espionage, scandalously neglected the 'counter-' part of their mission. While Five Eyes were eavesdropping on the cellphones of allied leaders, Russia conspired with the мокрые дела Candidate to secure the US Presidency, China stole the entire F-35 dataset from Lockheed and little Vlad, fresh from invading the Crimea, got a head start in buggering up Europe (with, admittedly, ample help from the British Conservatives' circus of Useful Idiots).
It worries me to agree with that loathsome ambulatory compost heap, Steve Bannon, about anything: but he is almost certainly correct that unless China changes its ways, which includes the seemingly impossible feat of regime change and a move to democracy, sooner or later it will have to be cut down to size.
Russia, ultimately, cannot win because its economy is a kleptocracy and a ruinously badly managed mess besides. China, ultimately, cannot lose because its economy is colossal and growing. Unless we actually want its murderous, repressive regime to enslave the world in a new Dark Ages, China must be stopped. If regime change through trade pressure doesn't work—and there's no sign of it, especially under this hopelessly incompetent White House—the answer will ultimately be military.
The consequences of war with China in the next five years are horrifying. The consequences of waiting ten or 20 years are much, much worse. And the consequences of doing nothing at all are the extinction of human freedom: everywhere.