This is the 1914th most frequent Arabic word.
للدفاع
"For defense" or "to defend."
Here, the word 'للدفاع' refers to the purpose of constructing the wall, which is the protection of the city.
أنشئ السور للدفاع عن المدينة.
The wall was built to defend the city.
In this sentence, 'للدفاع' indicates the necessity to develop a strategy for self-protection.
يجب أن نحتاج خطة للدفاع عن أنفسنا.
We must need a plan for our defense.
The term 'للدفاع' here reflects the soldier's readiness and commitment to protecting his country.