South Korea would really be in a pinch, Japan at least has some sea between, but little comfort beyond that. If these nations were smart they'd come up with their own answer to the BRICS just out of self interest...if two leading nations with a tangled history like South Korea & Japan were to approach Taiwan, the Philipines, Australia, New Zealand and the scattered Pacific island nations and form tighter economic, trade and military bonds (basically everybody not in the ASEAN orbit) I think that would be a positive thing.