First Indochina War
The French had the strategy of pushing Việt Minh into attacking a well-defended base in a remote part of the country at the end of the logistical trail. The strategy was validated at the Battle of Na San. The major problem of the war was the lack of construction materials (especially concrete). Because of difficult terrain without roads, tanks could not be used, and the providing of air cover was difficult. That made it almost impossible to defend the area effictively.