The threat to Al Shajara
It doesn’t take a military expert to understand that there are obvious problems with being surrounded. Apart from the issue of supplies, the defender in such a situation can be attacked from almost any direction. He must therefore distribute his forces fairly evenly along the whole perimeter, whereas the attacker can choose the time and place of the attack, overpowering the defender at that point.
If part of the perimeter is breached, the defender is easily flanked (attacked from the side or the rear). By contrast, in situations where the defender is not surrounded, he can retreat and regroup, maintaining a coherent battle line or other formation. This allows the defender to survive and fight another day, whereas a defender that is surrounded is at greater risk of complete annihilation or capture.
Fixed defenses are also easily targeted with…