Pretty much the only land a great circle JFK-NRT flight passes over is northern Ontario, Nunavut/NWT/Yukon, a little bit of Alaska, and Kamchatka. A great circle JFK-TPE changes that to Quebec, Nunavut, far-east Sibera, and Manchuria. (Of course, planes would take different routes for reasons like 'weather patterns' and 'restricted airspaces' and similar.)

So basically my point is this: the FAA has no jurisdiction over the vast majority of those routes.