> The limit lies in the needs of their own export oriented economies, which
> mainly export to the US.
This used to be the case, but nowadays East Asia trades much more with itself than with the US. Check out Tables 5 and 9 here:
http://www.efn.org/~dredmond/Geopolitics.html
This is 2000 data, but since then, intra-East Asian trade (especially with China) has continued to rocket to new heights.
-- DRR