It's fine that Lee Siegel decries the "savagery of wars produced by male egos." But he waxes sexist in concluding that biology dictates women's unsuitability for combat.
Siegel ignores the fact that many women opt to avoid motherhood and instead pursue occupations once held exclusively by men. His argument that wars should be fought by men alone is as specious as his contention that women should by virtue of their being protest war.
What Siegel apparently doesn't understand is that some women make superior soldiers, not to mention that some men can quite capably carry signs protesting war.