Complex sentence: The obverse to Progressive Ware is Unlimited War which includes civilian populations as legitimate targets of military action in the hope of influencing the populations will to fight along with their support for their leaders and secondly to thereby affect the policies of those leaders to continue the conflict.
Split into simpler sentences: The obverse to Progressive War is Unlimited War which includes civilian populations as legitimate targets. The aim of Unlimited War is to use military action against civilians in the hope of undermining the populations will to fight, to undermine their support of their leaders and thereby influence the policies of those leaders to continue the conflict.