Hydrogen weapon creating destruction (4)
I believe the answer is:
harm
'destruction' is the definition.
(thesaurus)
'hydrogen weapon' is the wordplay.
'hydrogen' becomes 'h' (H is the chemical symbol for hydrogen).
'weapon' becomes 'arm' (I've seen this before).
'h'+'arm'='HARM'
'creating' acts as a link.
(Other definitions for harm that I've seen before include "Hurt, maim" , "Damage, hurt" , "Detriment" , "Wound" , "Hurt, injure" .)