Respuesta :

(1) Poor supply lines 
(2) Out numbered 
(3) No escape route 
(4) Delayed reinforcements 
**History will show that any defencive position which is immobile can and will eventually be breached and over run.*** (ie. castles of England, Normandy beach heads, theMaginott Line, trenches in WW I)

(Resorces From Google)