Does every American soldier need to be able to fight the enemy? Yes. Next question.
I can't read the article (or even cut and paste the free teaser--thanks guys!), but the author (who I respect) clearly believes the answer is "no."
One, did we learn nothing from the 2003 Iraq invasion when our ill-prepared real echelon convoy got lost in enemy territory and was shot up for its troubles?
And two, have we forgotten that since the invasion a lot of support jobs were moved to civilian employees, already addressing the question in the affirmative to some extent, but making it far more important for those left in uniform to be capable of fighting the enemy?
Being capable of fighting enemies doesn't mean being capable of going on A-Team raids, but it damned well should involve defending your own position or fighting through an ambush.
[And yes, you may have seen this already when the scheduled posting function went wobbly and posted it earlier in time the same day before I noticed it. Sometimes that happens.]