He is an old man basically, and we all get stubborn in our old age. How is his eyesight and hearing?
Has he always been like this? Or is this behaviour fairly recent? Since he's grown older?
Sounds like it could be a combination of a few things.
He could be getting deaf....his eyesight could be bad -maybe. Or he could have some mild form of old-age dementia.
Be patient with him. Yes I know he must drive you nuts, especially if he's never behaved this way before. But if it is dementia, then he will be feeling a bit confused in himself.
Get a halter instead of a collar. This will give you better control over guiding him when you are on walks, and will put less strain on his neck, and throat so that if you have to hold him back firmly it won't hurt him.
Do take him for walks. Take him for as much exercise as you think he is happy with (bearing in mind his arthritis)
A few bits of kibble in your pocket is a good idea! Whenever he does anything good, or obeys you, give him a couple of bits. That might make a difference.
You could test his hearing and eyesight too, just to be sure if he can see and hear OK.
I met up with an old dog the other day sitting on someone's front lawn. I spoke to him, and he neither saw or heard me. I tried again -no reaction, though he looked content enough. Then I tried a more high-pitched sound. There was a vague reaction. So I did a few little whistles, quite high-pitched, and he heard me then OK. He wagged his tail. Some deafness isn't total, but only certain levels of sound can be heard.
He doesn't believe you are the leader. You need to be in control using positive means. Take something he loves with you on walks so you can pull it out and lead him where you want him to go when you need to. This might be a toy or his favorite treat.