You might not use undermining, but it's exactly what it is.
I totally disagree with everything you are saying here. Many people have bought in to the theory of BRICS and not looking at what is actually happening.
I think good things will happen from BRICS and it may serve as an alternative for poorer countries, but it's not close to becoming a real threat and if you subdue China the system is virtually squashed.
Undermining how?
De-dollarization is that undermining you are talking about.
Which in my opinion wont happen in the near future, but may be possible in the long term as China, India become bigger.
China and India cannot be subdued and they will become bigger.
The combined population of the west, is less than the population of China or India (individually).
They are markets on their own.
So in short, they are huge markets, huge economies, some of the major producers of the world, and nuclear powers to boot.
How will you ignore and brush off such a group? You cant.
They are not a threat per se.
But they will be power sharers in the future with the west.