position. In May the Chinese forces under Lu Han began to withdraw across the Sino-Vietnamese frontier. The French sought to move in quickly but were for the most part stymied. It was the wet season, and Giap’s troops were nimbler at navigating the difficult conditions and establishing control of the evacuated areas. Adept at sabotaging roads and bridges, they continually frustrated the road-bound French, delaying them long enough to take scores of important towns and villages out of play. Inevitably, there were military clashes.
