Opinion: The USA and Russia should be teaming up to take down China. Agree or Disagree?

Except that it would also take out the US with it if we did that.  The US is home to hundreds of global operations with China being one of the fastest growing middle classes to sell things to.  Every major US corporation not only makes things in China, they sell things in China.  GM is the second largest vehicle seller in China before VW.  US companies have invested billions in China, and all that would be lost.  It makes US companies more money, which translates into increasing stock markets and 401k's.  It decreases prices so consumers can buy more products, moving our economy along.
Russia is building a pipeline to China.  They too want in on the opportunities,  China is not going to attack anybody, like the USA or Russia has done in the past.  Only a fool would ignore the opportunities to increase their own domestic economy because they think that the world is some sort of competition for economy size.  It has to do with doing what is best for your own country, not being afraid of some silly ranking of economy.

As economies expand globally, all countries can benefit f/ the exchange of goods and services. The sharing should draw all of us closer as we learn to appreciate the only planet we have. Your talk of "taking one down" is disturbing.

No one is taking anyone down.