What have I missed
No diplomatic overflight clearance required: it's a massive issue which has prevented us (the RAF) from operating how we wish to. The lack of AAR assets is usually also 'a big issue' too.
It's far easier to get non strike aircraft permission to operate from foreign land. Afghanistan 2001, some ME countries allowed the tanker assets/nimrod to operate from their soil but the only FJ's we refuelled were off the carriers.