> Idealism is fine until it starts interfering with reality.

Idealism has been carving into reality nonetheless.

Our current standards of living are straight out of platonic Eidos, compared to those of our cave-dwelling predecessors.

Computers are also a perfect example of materialized ideals. Airplanes, Internet, space exploration, you name it.

Why should that stop at war for any reason other than someone having a deep vested interest in it?