> Finally, can it be flown legally? Most of the trajectory can pass over the oceans, but skipping land completely would take too much of a detour, and likely be incompatible with prevailing winds. Although the political climate may be hostile, it is still legal to fly civil craft over other countries.
So no, it's not legal in many ways.
"Finally, what are the legal implications of flying an airship drone over foreign air spaces? This very complex area clearly requires in-depth study and careful consideration, and it lies completely out of my depth. The primary objective is just to avoid being shot down since I'm not planning to visit any foreign countries in person, so allow me to just touch over the main issues."