Valluy had failed to destroy the Viet Minh through a knockout blow and realised that he was now facing a long war. With limited manpower, he was unable to launch large-scale attacks against the Viet Minh, and 1948 saw him consolidate the gains of the previous year, including the thin string of forts along Route Coloniale 4 (RC4), a circuitous road through ravines and over mountain passes between the towns of Lang Son and Cao Bang. By the end of 1948, French forces had suffered over 30 major ambushes along RC4.