You got all upside down, as usual, Brad. The right question is not whether the US involvement has beneficial effect on a nation's development, but whether the *absence* of it does. The fact that for geoplitical reasons Washington could not pursue in Asia the same imperial policies they did in Latin America may explain why Asia succeeded whereas Mexico (that also had a very weakened landed gentry as Taiwan and South Korea) did not.
IMHO, the US of A is signularly the most serious instituitonal obstacle to world & human development.
wojtek