The point is, if "only 10% of 1.6B Muslims would let themselves become "radicalized jihadis", (as if that meant anything) "enlist" or become a lone wolf to destroy the infidel, that would be more than enough to wreak havoc to take over the world, even if the remaining 90% simply send those at the sword's edge care packages and say prayers at their mosques. Good point.
A big difference in fighting a war involving uniformed soldiers and Muslim aggression, is the Muslims would be in our midst and render our military obsolete.
Kafirs would be fighting Muslims in Kafir communities and probably fighting family members who submitted to Allah.
A totally different kind of combat. -Tom