A ksatriya should not be a coward, and he should not be nonviolent; to rule over the country he has to act violently
SB Canto 4
In Bhagavad-gītā (3.9) it is said, yajñārthāt karmaṇo 'nyatra loko 'yaṁ karma-bandhanaḥ: one should act or work only in order to please the Supreme Lord, otherwise one becomes entangled in the resultant reactions. According to the four divisions of varṇa and āśrama, kṣatriyas and vaiśyas are especially advised to perform great ceremonial sacrifices and to distribute their accumulated money very liberally. Dhruva Mahārāja, as a king and ideal kṣatriya, performed many such sacrifices, giving very liberally in charity. Kṣatriyas and vaiśyas are supposed to earn their money and accumulate great riches. Sometimes they do it by acting sinfully. Kṣatriyas are meant to rule over a country; Dhruva Mahārāja, for example, in the course of ruling, had to fight and kill many Yakṣas. Such action is necessary for kṣatriyas. A kṣatriya should not be a coward, and he should not be nonviolent; to rule over the country he has to act violently.
Kṣatriyas and vaiśyas are therefore especially advised to give in charity at least fifty percent of their accumulated wealth. In Bhagavad-gītā it is recommended that even though one enters the renounced order of life, he still cannot give up the performance of yajña, dāna and tapasya. They are never to be given up. Tapasya is meant for the renounced order of life; those who are retired from worldly activities should perform tapasya, penances and austerities. Those who are in the material world, the kṣatriyas and vaiśyas, must give charity. Brahmacārīs, in the beginning of their lives, should perform different kinds of yajñas.