Fixed fortifications are easily outflanked and destroyed by mobile armored assault

Evidence

You can keep your stovepipe and all that goes with it. Along with the first armored units you’ll have engineers and motorized sections right away—and tough ones. And those bastards won’t come by the road, either: they’ll go around. They’ll come and knock very politely at your bank-vault door, but after a couple of hand grenades you can say good night. — Julien Gracq, Balcony in the Forest, 169

Categorization

• corroborated: 2 independent passages support this claim — Julien Gracq, Balcony in the Forest, 169