Damon Linker complains about just war theory:

Is there any realistic scenario in which, judged by these criteria, the 21st-century United States would start and wage a war that it didn’t consider just? [bold mine-DL]

I submit that the answer is an unequivocal no. We always have a moral rationale for undertaking military action. We always consider our actions defensive (even if the aggression hasn’t happened yet) and aimed at protecting the innocent. We always think we have a reasonable chance of success. We always consider ourselves to be a competent authority. And we always claim to have waited as long as possible to act.

Linker is mixing up two different things here. He’s correct that all states, including ours, will normally portray their decisions to use force in the best light possible. Self-serving war propaganda is practically as old as war itself. As with anything else, just war theory can be and has been abused, not least by some American Christians that have sought to rewrite the requirements in order to allow the U.S. to do more or less whatever it wants in the world. That makes taking the requirements of just war theory seriously all the more important. Consider the requirement that war be waged only as a last resort. This is one of the most often ignored requirements nowadays, but it is the one that shows us that preventive war is inherently unjust. No matter what a government may say about waging a preventive war, it cannot ever meet this requirement, because it is simply not possible to wage such a war after all other options have been exhausted. The decision to wage preventive war is the decision to ignore and dismiss important parts of just war theory as irrelevant.

It is commonplace for states to commit acts of aggression and then claim they were acting in self-defense, but what matters for the purposes of determining whether a war is justified is what the state has done, not what it has said about its actions. According to the traditional requirements, a war must also not create greater evils than the ones that it is being fought to remedy. Preventive war can’t ever meet this standard, either, because preventive wars are fought in order to eliminate supposed threats that do not yet exist. In these cases, “lofty” reasons for using force are just excuses to commit acts of aggression against another state.

As Linker notes, Nigel Biggar seems to be interested in coming up with these excuses:

The U.S.’s default setting is to careen toward conflict, but Biggar believes it’s necessary to step harder on the gas because he fears that a “presumption against war” has taken hold in the Western world. (Reading his book, you’d think that the foreign policy establishments of the U.S. and U.K. were dominated by pacifists.) In Biggar’s view, this presumption focuses too single-mindedly on the “terrible evils” wrought by war while downplaying the fact that not going to war permits evils of its own.

It should therefore come as a surprise to no one that Biggar concludes with his book with an attempt to defend the merits of the invasion of Iraq. Linker understandably responds to this conclusion by throwing up his hands in disgust: “I’m going to go out on a limb here and simply declare that any moral calculus that gives such a result is effectively worthless.” He’ll get no argument from me on this point, but it would be wrong to throw out just war theory because someone chooses to interpret it so atrociously. There’s nothing new about warping and distorting just war theory to support the Iraq war, but no one should assume that an honest interpretation could ever justify it.

The only way to conclude that invading Iraq met all the requirements to be considered a just war is to reach that conclusion first and then to twist and distort the requirements as much as necessary. As Linker goes on to show, the Iraq war fails to meet several of the requirements to be a just war. The problem he identifies is not with “advocates of just war,” but with people that take interest in the subject in order to get the U.S. and its allies into as many wars as possible. Linker isn’t really arguing with “advocates of just war” at all, but with interventionists that want to cherry-pick and abuse the concept of just war for the sake of interfering in the affairs of other nations.