Reviewed: Useful Enemies: When Waging Wars Is More Important Than Winning Them by David Keen (Yale University Press, 312 pp., $38). Heraclitus said that war is the father of all things, and though the great Greek’s utterances are  wisdom for the ages, this one-liner is way past its sell-by date.

Sure, war is undeniably the big daddy of bigger military budgets, of opportunities for pillage and plunder, of ways to keep busy unemployed young men who might otherwise be politically restive. War is also a pretext for cracking down on internal enemies, and for the psychological rush that wielding a gun can give. It’s just that war is no longer the proud papa of “national defense” or “security,” archaic pursuits that are rarely even afterthoughts to many of the world’s violent conflicts today.

David Keen’s altogether excellent Useful Enemies: When Waging Wars Is More Important Than Winning Them aims to make sense of this apparent senselessness. It was while doing extensive aid work in war-ravaged Sierra Leone that Keen (now a professor at the London School of Economics) noticed that old notions contest, fought for territorial control or political power, just didn’t seem to apply to the violence around him.

Government soldiers cheerfully sold weapons to rebels with whom they tacitly collaborated on mining, smuggling, and rape. Most of the violence was against civilians, and neither side in the conflict seemed particularly eager to win. Keen, who has also worked in Guatemala, Sri Lanka, and Sudan—and who knows his way around a library as well—uncovers the irrational but coherent logic that drives warmaking all over the world, in the process overturning many basic assumptions about what war is for and about.

Keen’s research has also taken him deep into the United States, and the application of his thesis to the world’s greatest military power is bracing. A desire for mere “winning” is clearly the smaller part of our cherished habit of far-flung military adventurism, a habit that yields consistently crappy results. Korea ended where it began (the North considers it their victory), Vietnam was a bust, and it’s hard to think of our two-decades-long Iraq war as a “win.” And when we do drag our tails out of Afghanistan and the Taliban reassumes some role in government there, this too will be less than a victory. Yes, we’ll always have Grenada. Still, you’d think that after this remarkable record of military failure, alternatives to near-constant warfare might come into style in Washington.

Instead, U.S. foreign policy grows ever more militarized: “Defense” spending dwarfs the State Department’s budget by roughly 30 to 1, and most Republicans would love to slash State further. Meanwhile, our more “serious” Democrats suffer from war-induced penis envy, a disease treated by outflanking the GOP to the right whenever possible. (Four years ago, both Mitt Romney and John McCain condemned as reckless a certain Illinois senator’s pledge to expand the Afghan war into Pakistan.) The net result is that any serious attempt at the thing called diplomacy—say, with Iran—is hysterically anathematized as “another Munich.”

What drives this permanent state of semi-war is not security or (don’t laugh) strategy, but our militantly uninformed domestic politics, our robust military-industrial complex, and our desperate need to find a use, no matter how foolish, for all the shiny hardware on which we’ve dropped so much coin.

After all, why did we drop more than two million tons of bombs (about the same tonnage dropped in both the European and the Pacific theaters of the Second World War) on little Laos in 1968? As then–U.S. Ambassador to Laos G. McMurtrie Godley told journalist Fred Branfman, “You gotta understand, Fred—we had all those planes coming in to Laos. What could we do? We had to bomb villages.”

Chase Madar is an attorney in New York and the author of The Passion of Bradley Manning: The Story of the Suspect behind the Largest Security Breach in U.S. History, published by O/R Books.