Nonetheless the ksatriyas had to perform such undesirable actions (fighting and killing) as a matter of duty

Expressions researched:
"Nonetheless the kṣatriyas had to perform such undesirable actions as a matter of duty"

Srimad-Bhagavatam

SB Canto 4

It is clear herein that the king sometimes has to perform duties which are not very desirable just because he is the king. Similarly, Arjuna was not at all willing to fight because fighting or killing one's own kinsmen and family members is not at all desirable. Nonetheless the kṣatriyas had to perform such undesirable actions as a matter of duty.

SB 4.24.6, Translation and Purport

Whenever Antardhāna, the supreme royal power, had to exact taxes, punish his citizens or fine them severely, he was not willing to do so. Consequently he retired from the execution of such duties and engaged himself in the performance of different sacrifices.

It is clear herein that the king sometimes has to perform duties which are not very desirable just because he is the king. Similarly, Arjuna was not at all willing to fight because fighting or killing one's own kinsmen and family members is not at all desirable. Nonetheless the kṣatriyas had to perform such undesirable actions as a matter of duty. Mahārāja Antardhāna was not very happy while exacting taxes or punishing the citizens for their criminal activities; therefore, on the plea of performing sacrifices, he retired from the royal majestic power at a very early age.