Ambush & Surprise Attacks

What links these battles?

Surprise is the cheapest advantage in warfare and one of the hardest to arrange. The battles here were decided before the fighting properly began, by armies that were hidden, misread or simply not expected. Hannibal trapped a Roman army in the fog at Lake Trasimene; Arminius destroyed three legions in the Teutoburg Forest; Washington crossed the Delaware on Christmas night to fall on Trenton; and the Tet Offensive struck across South Vietnam during a holiday truce. Each entry looks at how the surprise was achieved and, just as importantly, why the victim failed to see it coming.