 Bergonzoli knew that if Bardia and Tobruk held out , a British advance further into Libya eventually must falter under the logistical difficulties of maintaining a desert force using an extended overland supply line . Not knowing how long he had to hold out , Bergonzoli was forced to ration his stocks of food and water so that O 'Connor could not simply starve him out . Consequently , hunger and thirst adversely affected the morale of the Italian defenders that had already been shaken by the defeat at Sidi Barrani . So too did medical conditions undermine morale , particularly lice and dysentery , the results of poor sanitation . 
