This is generally true but if it's the roots and soil that's causing the problem then leaving as is is certain death. Repotting is only possible death. I know which one I choose.
I agree but in this case, the tree is not in bad soil from the pictures. It might be pot bound but it looks to me that the tree isnt getting enough water.
@WaterLily You can try to get more water into the soil by GENTLY poking some holes into the soil to get more water penetration in there.
Pines like a open soil that drains well. It looks like it is in soil that is lava and pumice with some pine bark mixed in?
For one, I think the pot is too small and could use a bit bigger pot, particularly if it is very root bound.
You are in Arizona, it should be pretty close to repotting season for you now? Cam you tell if the branches with green needles have buds that are swelling?
The best option is to use a mix similar to that it is in and do a gentle repot into a bigger pot.
Take it out of the current pot and gently remove the soil around the outer edge of the current root ball. I wouldnt remove more than half an inch around.
Put it in the new pot, wire it in so it doesnt fall out and fill the gaps with the new soil. Water it well afterwards then use the chopstick method I described.
You are probably going to lose those branches with the dead foliage, they are probably dead already because I dont see any buds but it could just be the picture. Just leave them be for now and see what happens. There is still healthy looking needles so the rest of the root ball might be ok for now but a repot as I described above would be a good idea. After that you will want to protect the tree from frost and freezing. Putting inside a shed or a garage if that happens would be the best option, not in your house that is 65+ degrees.
Hope it pulls through for you, good luck