One of the key insights from Charles and Demy’s book is the shift in just-war thinking since World War II. The just war tradition used to proceed on a presumption against injustice. When injustice occurred coercive force could be used to correct that injustice. The use of coercive force would not only be just, but a necessary act of love. We all understand this in domestic situations. If a man steals another man’s car an injustice has occurred. Force could be used to correct that injustice. To allow the thief to go free for the sake of peace is morally repugnant.

But since WWII there has been a move or rather a subversion of just-war thinking where now the presumption is not against injustice, but against force, violence, and war itself. The authors spend quite a bit of time addressing this shift. They do not see it has  good one. It is not in keeping with just-war tradition and most importantly sides with the oppressor and leaves the weak trodden underfoot. Here are a few quotes from early in their book which address this shift.

Thus already in 1960, Roman Catholic theologian John Courtney Murray could write that the use of force was no longer considered a moral means for redress of violated legal rights. The justness of the cause, he worried, has become “irrelevant, ” and [the words in quote marks are from Murray. Bold mine]

“There simply is no longer a right of self-redress; no individual state may presume to take even the cause of justice into its own hands. Whatever the grievance of the state may be, and however objectionable it may find the status quo, warfare undertaken on the sovereign decision of the national state is an immoral means of settling the grievance and for altering existing conditions.” [End Murray quote]

What Murray conceded is applicable to the present day. There exists today-perhaps less so among laypersons but overwhelmingly so in academic circles and in many religious circles-a presumption against war and force in general rather than a presumption against injustice. 

After citing numerous sources that agree with this shift, including the 1983 statement by the U.S. Catholic Bishops The Challenge of Peace, Charles and Demy say this

The authors assume that peace is the starting point for thinking about justice and that force cannot be a moral entity…the just-war tradition, however, proceeds on a different assumption. Without justice, peace itself can be illegitimate. Again, in the words of Aquinas, “peace is not a virtue, but the fruit of virtue.” The animating spirit of just-war thinking, properly understood, is that “social charity comes to the aid of the oppressed.” [Citing Paul Ramsey] Therefore, if we categorically rule out the possibility of war or coercive force, we then categorically rule out intervention, which may on occasion be an requirement of love rightly construed. The just-war tradition, hence, strongly qualifies “peace” by acknowledging that if this “peace” is not justly ordered, it may well be illegitimate, even oppressive…As thinkers such as Aquinas and Suarez argue, those who wage war in just manner are not opposed to peace, unless, of course, it is an evil peace.

The authors of these sundry statements [denominational papers against war] mistakenly assume that the just-war tradition begins with a presumption against war; however, this reveals a basic misunderstanding of the tradition.  In its moral justification, the classic just-war position issues out of a presumption against injustice and evil…The just-war position proceeds on the assumption that coercive force per se is not evil and that its application depends on the moral character of those employing it. Correlatively, it understands that there are occasions arising from gross injustice in which, reluctantly, we may need to apply coercive force, even if this means going to war, for the protection and preservation of a third party.