What's War For?

A great deal of destruction goes on in war. Innocent lives are taken, cities flattened. So much so that people sometimes become confused and come to believe that destruction and killing is the point of war. But there are troubling questions associated with this view.

In the 18th century almost a hundred years-worth of wars were fought in Europe in which collateral damage was minimal. Small professional armies contended in carefully selected battlefields - often chosen to be far from populated areas. Random destruction was kept to a minimum. If war is about destruction and killing, how could these wars have all been fought so wrong-headedlly?

It's also peculiar that the Rules of War and Just War Theory both extend protections to innocents. Why would you set up an activity whose aim is to kill and destroy with rules that make it more difficult to kill and destroy?

Finally, there is an evidentiary problem: there is only one war (that I can find) which was fought with the goal of killing everyone and destroying everything. The Romans destroyed Carthage utterly and killed upwards of 90% of her citizens (and sold the rest into slavery.) If war is about killing and destruction, why aren't there more wars like this? Wars of extermination.

The truth is that war is about coercion. It is about getting other people to do what you want. Give me the gold. Let me occupy your land. Practice religion the way I do. Follow my forms of economic structure. Apologize. Leave me alone. These are all frequent aims of war and have been again and again throughout human history. The truth is that war is hardly ever about extermination.

The question of what war is matters because nuclear weapons are tools. How is it possible to know if you have the right tool for the job if you're confused about what the job is? 

A sledgehammer is a really powerful tool (measured abstractly) but it is entirely inappropriate if you're trying to do brain surgery.