Surely, it's going to vary where you are in the world. Remember the British spotters in Dubai
https://www.theguardian.com/world/20...ecurity-claims and Greece
https://www.theguardian.com/world/20...ecurity-claims?
You might think some places are OK and others obviously "dodgy". At least you might think so. However, here's a thought for you. At the Reno Air Races and also Oshkosh photography is fine. Wander among all sorts of planes, including military, with few, if any, barriers and take as many photos as you want. Then I go and sit in a US airport lounge, take a picture of a Beech 1900 that pulls up in front of me and the co-pilot appears in due course to ask me what I was doing; he was friendly but it was a warning.