Seems like for the US, the cost-benefit of running global hawks against manned airframe are not really there, it makes sense since at that scale, a UAV platform is not much cheaper than a manned version, the U-2 outliving its successor.
This is despite the insane endurance advantage global hawks have over U-2s (over 3x flight length). Although they are also getting replaced by MQ4C-tritons.
Seems to me like the role of HALE UAVs can be partially replaced by SAR equipped satellites flying overhead in a maritime scenario.