The term 'war crime' emerged after World War II with the signing of the Geneva Conventions (1949). It was aimed at protecting civilians during war conflicts. Because they are not supposed to be responsible, guilty or involved in these actions.

However for some reason this does not apply to men who are subject to forced mobilization.

Only volunteers can take part in war conflicts. Sending men to the front against their will, where they may die or be injured, is nothing but violent coercion to the potential death of the male civilian population. Regardless of what arguments any state gives! If it is a 'civic duty', then why only for male citizens? That's why forcible mobilization should be considered as a war crime.