Standard lack of elite soldiers! (4)
I believe the answer is:
norm
'standard' is the definition.
(I know that norm is a type of standard)
'lack of elite soldiers' is the wordplay.
'lack of' becomes 'no' (lack of money is no money).
'elite soldiers' becomes 'rm' (Royal Marines. I am not sure about the 'elite' bit.).
'no'+'rm'='NORM'
Can you help me to learn more?
(Other definitions for norm that I've seen before include "Required or acceptable standard" , "expected thing" , "Expected standard" , "(The) accepted way" , "Standard considered to be representative" .)