QE is basically expansionary monetary policy, no different in its effects (if it works) from reducing the policy interest rate. Yes, it tends to weaken the exchange rate; but it also increases domestic demand.
China is engaged in currency manipulation, that is, buying foreign currency to keep the yuan weak; meanwhile, it is actually moving to reduce domestic demand, among other things raising interest rates.
So the United States is moving to expand world demand, with a policy that may weaken the dollar; China is moving to reduce world demand, with a policy of deliberately weakening the yuan. America’s policy may annoy its trading partners, but they are not the target; China’s policy is predatory, pure and simple.
No equivalence here.
Clear explanation on differences between QE2 and China’s yuan manipulation.