Almost everyone is incredulous at my pacifist opposition to so-called “defensive war.”  In last week’s debate, Ilya Somin’s case began with this supposedly clear-cut case of legitimate war.  What could possibly be wrong with a country using military means to expel a foreign invaders?

My answer: the same thing wrong with every war

Premise #1: “Defensive” wars have very high short-run costs – most notably aggression against innocent bystanders.  Calling a war “defensive” doesn’t change the hard fact that defensive wars always recklessly endanger innocents – and usually deliberately target them.  See the American Revolutionaries’ treatment of Tories, most of whom were guilty of nothing beyond dissent.

Premise #2: “Defensive” wars have highly uncertain long-run benefits.  In particular:

a. The defenders often lose.
b. The defenders can often win with non-violent resistance, or merely by waiting.
c. Armed resistance usually provokes the invader to considerably greater brutality against the occupied population, both during and after hostilities.
d. The peacetime policy difference between the native and foreign regimes is often small.

As usual, if you’re very confident that these uncertainties don’t apply to a particular case, reflect that (a) people tend to be very confident on these matters even when they’re dead wrong, and (b) hindsight is 20/20.
Premise #3: It’s wrong to aggress against innocents unless the long-run benefits heavily outweigh the short-run costs.

Conclusion: Defensive war, like war in general, is rarely morally justified – and we aren’t very good at spotting the exceptions.

If you have trouble understanding what might motivate my skepticism, see almost any war of “colonial liberation” against foreign occupation – including, of course, the American Revolution itself.  See Chinese resistance to Japan in the 30s and 40s – millions of Chinese died so a native-born Chinese dictator could murder even more.  For that matter, see Japanese resistance to the U.S. in World War II.  Vast numbers of Japanese soldiers died to defend mainland Japan from the horrible fate they imagined the Americans invaders had in store for their families.  If the Japanese had surrendered sooner, vast horrors culminating with Hiroshima and Nagasaki would have been avoided.

If you think I’m cherry-picking, here’s a bitter lemon of an example: What would have happened to Soviet-occupied Eastern Europe after World War II if the people of the occupied countries began an all-out guerrilla war against the Red Army?  Terrible as Stalinist occupation was for Eastern Europe, who will say with confidence that the consequences of violent resistance would have been better?