But is there an easily spottable army? Can't they just disappear into the populace when they know the Americans are coming? It seems like they've been hiding am

But is there an easily spottable army? Can't they just disappear into the populace when they know the Americans are coming? It seems like they've been hiding amongst that populace anyway. And they've had another 20 years' time to gather and train recruits. If I were a war general tasked with solving this, maybe just track all the baddies' pickup trucks via drone/satellite when they "disappear", and send the firepower to destroy them..