One of the odder aspects of present-day politics is the assumption that if you are antiwar you are on the left, and if you are conservative you are “pro-war.” Like labelling conservative states red and liberal states blue, this is an inversion of historical practice.

 

The opposition to America’s entry into both World Wars was largely led by conservatives. Senator Robert A. Taft, the standard-bearer of postwar conservatism, opposed war unless the United States itself was attacked. Even Bismarck, after he had fought and won the three wars he needed to unify Germany, was staunchly antiwar. He once described preventive war, like the one America is being pressured to wage on Iran, as “committing suicide for fear of being killed.”

 

Conservatives’ detestation of the war has no “touchy-feely” origins. It springs from conservatism’s roots, its most fundamental beliefs and objectives. Conservatism seeks above all social and cultural continuity, and nothing endangers that more than war.

 

In the 20th century, war brought about social and cultural revolutions in the United States, including a large-scale movement of women out of the home and into the workplace. Nineteenth-century reformers had labored successfully to make it possible for women (and children) to leave the dark satanic mills and devote their lives to home and family, supported by a male breadwinner. The Victorians rightly considered the home more important than the workplace. A man’s duties in the world of affairs were a burden he had to carry to provide for his household, not something women should envy.

 

This happy situation was overturned in both world wars as men were drafted by the millions while the demand for factory labor to support war production soared. Back into the mills went the women. The result was the weakening of the family, the institution most responsible for passing the culture on to the next generation.

 

The threat war poses to the cake of custom is exacerbated by one of its foremost characteristics: its results are unpredictable. Few countries go to war expecting to lose, but wars are seldom won by both sides. The effects of military defeat on social order can be revolutionary...