I think the idea is that even if all the current top emitters do take initiative, China and India's emissions are expected to grow quickly. The losses will win over the gains.
If you think in terms of net change relative to a given level of emissions at some year... eu bad, US badder, China & India Terrible.
If you think in terms of "every person is entitled to X emissions per year," where X is current or desired average emissions (inc 0-emissions) then... China & India are best, EU & US are bad.
The more nationalistically we think of these things, the more nationalistic they seem and become.
That's quite outdated; there's a huge internal market in China, India, etc, and plenty of trade between the non-"1st world" countries. In fact, the US did have an initiative to reduce consumption from there (in the form of tariffs) and it didn't impact their economy much.
Just as an example, China now has about as many cars as the US. And the market there keeps growing, whereas the US has mostly plateaued.