In Japan, I took photographs of trains, buses, railway lines with no one on them, and the police just ignored me or smiled and gave me a thumbs up.
Interestingly, if I had to rate the approachability of cops, I'd put Japan > UK >> USA. And tbh, that's far down the list. In America, you try to avoid the police, even if you're law abiding. In the UK, you might have a chat.
After the morons started driving vans into crowds and attacking them with knives they stepped up armed officer patrols at busy times in my local city center.
My stepson was frightened as he'd never seen anyone wandering around with a gun before so I took him over and said hello and he was asking the copper all the awkward questions a young kid would :).
After that he started waving at them (and they have always waved back).
It's sad we have to have heavily armed officers on foot patrol but by and large they are damn good at their job.
Also the criteria for been an armed officer is quite strict, you have to be a full officer after probation (2 years) and a volunteer and physically fit then you get extra training.
If you do have to shoot someone you are automatically took out the field until the IPCC has gone over it in detail.
It's not perfect, nothing human is but it's a good balance.
Interestingly, if I had to rate the approachability of cops, I'd put Japan > UK >> USA. And tbh, that's far down the list. In America, you try to avoid the police, even if you're law abiding. In the UK, you might have a chat.