Empirical Experiment: The Twentieth Century.
War: outcome, 60 million dead. Imperial German regime gone. Nazi German regime gone. North Vietnamese regime a gang labor boss for Nike. North Korean regime combines all the delights of hereditary monarchy with those of high Stalinism.
Economic Growth: Annual world GDP today: $30 trillion; annual world GDP (2000 prices) in 1900: $3 trillion.
Net effect of war? 60 million people dead. No utopias created.
Net effect of economic growth? A much richer (albeit more unequally distributed) world with higher levels of education, less hunger, and longer life expectancies.