It's rational at the individual level, irrational at the group level.
The issue is you can't easily enforce cooperation without some external overarching force (e.g. regulation), especially across competing powers.
Refer to nuclear arms race in general. A specific example on why not to be the only one to cooperate: Ukraine gave up nukes in order to push for group level rationality, gets walked over as an individual. Oversimplifying, but yeah that's the rough point.
The issue is you can't easily enforce cooperation without some external overarching force (e.g. regulation), especially across competing powers.
Refer to nuclear arms race in general. A specific example on why not to be the only one to cooperate: Ukraine gave up nukes in order to push for group level rationality, gets walked over as an individual. Oversimplifying, but yeah that's the rough point.
Meditations on Moloch is a favourite of mine on this (albeit very depressing): https://www.slatestarcodexabridged.com/Meditations-On-Moloch