Zombies, and the fighting thereof, has caught the attention of James R. Holmes, house writer on matters military for RealClearDefense. As he describes the special, atypical characteristics of fighting the "undead," I am reminded of GI reminisces of the Chinese involvement in the Korean War.
Our GIs in Korea had similar, albeit not identical, adjustments to make in military doctrine when confronting an enemy that relied heavily on throwing masses of poorly armed troops at Allied lines. Overheating machine gun barrels became an issue as Chinese dead and dying piled up in mounds over which scrambled following waves of semi-armed suicide troops, picking up weapons dropped by dead comrades and continuing to charge, waving swords and blowing bugles and whistles.
Not too different from zombie warfare, eh? The same issues of adjusting - to lower levels of sophistication - one's military doctrine, to something akin to Napoleonic War levels.
When your opponent's uniforms are quilted cotton and tennis shoes in the snow, and they don't have enough weapons for everyone, you're fighting near-zombies. As Holmes notes, they too were an enemy with whom we could not treat or bargain, at least in the short run the only two possible coping strategies were retreat or mass murder on an industrial scale. The U.N. forces in Korea did quite a lot of both.