Judging when a state's resort to violence is necessary in defense of national interests is hard to do.
Hard to disagree given that wars often go awry:
Wars, therefore, should be rare and utterly necessary.
The author contends that America's wars after World War II largely fail that test and result in defeat. I'm pretty sure that is false, at least on victory, but I respect the author. He has good points about the principle and figuring out how to fight a particular war.
I readily concede that going to war doesn't have to mean hundreds of thousands of troops in direct combat. That should absolutely be up for debate. As long as you realize a potential problem with that is failing to win quickly with overwhelming force and risking endless escalation to more expensive stalemate.
But sure, we should absolutely pace ourselves where we can.
More fundamentally, how do you
know what is utterly necessary or not? What is "another Vietnam" and what is "another Munich"?
Who would have gone to war with Germany over the Rhineland as utterly necessary? Or over the Sudetenland?
Face it, if the Western Allies had gone to war between 1936 and 1938 and quickly defeated still-weak Nazi Germany, people would have argued the easy victory proved the war was unnecessary.
Without knowledge of the future between 1938 appeasement and 1945 global war and genocide, killing baby Hitler is a cruel and repulsive crime. As would be a war on the German people over one odd and admittedly distasteful little Austrian corporal who was talking big.
And of course, many in the West agreed that the Versailles Treaty was too harsh on Germany. The poor babies.
By all means, war should be rare and utterly necessary. Make efforts to make war both. But the "last resort" standard is not the answer. You can always cling to hopes of peaceful resolution, no matter how slim:
This is why the anti-war side's constant refrain that military force must be a last resort rings so false to me. When you believe that any path, no matter how unlikely to bear fruit, keeps you from that "last" resort, then military force is practically speaking never an option.
And that issue gets complicated even more, really.
So have some sympathy for the decisions of leaders who can't see the future with the clarity of seeing the past.*
*And Hell, we're not very good at that, either. Which is why I have sympathy for the people of Russia whose paranoid rulers see baby Hitler everywhere they look in the nursery.