I've only seen that a few times in the last year. It's new to me. I think I saw Iraqi troops wearing some like that.
I see. Have the jamming devices always been individually carried?
Not entirely. I read that Tomcats were designed with some strike ability but, this was not used until the later stage of their service. There are some photos online of Iranian Tomcats with a rocket pod and bombs. American examples were used as bombers.
Iranian F-14s achieved air-to-air kills...
That's a good analysis. It seems that nuclear propulsion is only suitable for very large aircraft and even then, only with airports or airbases that are specially prepared for them.