The effectiveness of resistence fighters directly correlates to the ROE of the invading country. If the ROE are lax, as they were in WWII, and there is an extensive use of terror tactics to suppress the public, then yes, resistence would be futile. HOWEVER, as we are experiencing now-if the occupying forces play by humane rules-no intentional targeting of civilians, no resorting to terror tactics (I dont want to get into the politics of it), then, the general populace will support them. If they know that there will be limited, if any, retaliation by the occupying army, then they REALLY have nothing to lose. In fact, they benefit from BOTH sides-if the resistence isnt also targeting the populace, then they are likely bribing locals with food, water, money, or resources. Likewise so would be the occupying army. So, your loyalty would lie with whoever pays the most. This is something we are constantly fighting with now-your average farmer in the mideast is poor-not developed country poor, but POOR. So, the promise of a month's supply of food is valuable to them-and they will switch loyalties so long as they continue to get the goods to survive.