As an aside to the thread, in my attic there are probably the artillery manuals issued in around 1960 (perhaps earlier) from which we were taught how to plan and fire the Chemical shells that we, ummm, didn't have, as well as the manuals for the 8" Howitzer nuclear shells, and free-flight self-propelled missiles with nuclear warheads, that we did have. Both these were tactical rather than strategic weapons, deployed in West Germany for use when needed.
A 5KT shell/warhead would be quite useful against ISIS, I would think, if a bit of collateral is acceptable. 3rd degree burns within 1500m (airburst), plus a bit of residual radiation/fallout, should keep them quiet for a bit. Just sayin'.
Not a lot of people know that overpressure of 150 psi is required to kill the average human; the good news is that, from my notes, this overpressure does not occur with nuclear warheads except at a distance from GZ at which death will result from other effects.
So that's alright, then, apart from the secondary effect of being killed by or injured by being blown about or hit by falling masonry, which can happen with overpressure of as little as 7 psi. Amazing, eh?