raas767:
That's not true. Here's a partial list of fifth freedom routes on the Pacific side, NZ has MEL-LAX and LAX-LHR. QF has LAX-AKL. RG has flights to Japan via LAX. Both KE and JL have flights to Brazil via the US. CX has flights to Vancouver from JFK. MH has TPE/NRT-LAX, and used to serve Mexico City via LAX. TG has KIX/NRT-LAX. Also SQ has HKG-SFO and TPE/NRT-LAX. On the Atlantic side, there are even more.
When the US signs an open skies agreement with a country, by definition, airlines from that country can fly any fifth freedom routes.