That, too, is a plausible explanation. I had not though along those lines. Young "unripe" jihadis willing to die for their "cause". But, does "green" have the same interpretation in their language/culture as ours, i.e. green = unripe?
It doesn't turn on that, but on whether the author knows the usage of green as unripe in English and whether Arabic applies its word for unripe (as in fruit) to human beings to mean inexperienced.
lahargis, do Arabic speakers use the Arabic word for 'unripe' to mean inexperienced?