ولو فرضنا عدم الواسطة لا يبقى ذلك مأمورا به
If the intermediary basis for an act's goodness is absent, the command does not remain applicable on that basis.
If no qualifying offense has occurred, the corresponding penalty does not arise. Likewise, a legal reason for armed conflict cannot be replaced with a free-standing desire for warfare.
The same logical form appears in non-penal examples: someone already at the mosque needs no new journey; someone already ritually pure needs no new ablution solely to recreate an existing condition.
The decisive question: does the required objective or legally relevant ground still exist?