Please read Quote from the book “Bhagavad Gita and Hinduism, What Everyone Should Know”
BHAGAVAD GITA ADVOCATES WAR?
There are some who may agree that the war was indeed a 'Dharma-War' but may hurriedly conclude that the Bhagavad Gita advocates war. The apostle of peace, Mahatma Gandhi, who shaped his non-violent freedom struggle, could not have considered the Gita as his life-guide, if it really advocated war. The employment of non-violent struggle was unheard of until Mahatma Gandhi employed it against the British. His success has transformed the political struggles around the world ever since. Mahabharata supplies enough evidence to prove that both Pandavas and Lord Krishna did everything that could be done to avoid the war. Also from the first chapter of the Gita, it is clear that Arjun preferred not to fight; war-mongering was the last thing in their characters. They desperately wanted to avoid the war.
In his poetry Four Quartet referring to the Gita, T S Eliot has given uncannily accurate message of the Bhagavad Gita: “Without consideration towards result, just fare forward, not fare well but fare forward”. The Bhagavad Gita does not advocate the war but it advocates righteous action without caring for the consequences.
Swami Prabhupad's remark is useful to further understand: “On perusal of the first chapter of the Bhagavad Gita one may think they are advised to engage in warfare. When the second chapter has been read it can be clearly understood that knowledge and the soul are the ultimate goals to be attained. On studying the third chapter it is apparent that acts of righteousness are also of high priority. If we continue and patiently take the time to complete the Bhagavad Gita and try to ascertain the truth of its closing chapter we can see that the ultimate conclusion is to relinquish all the conceptualized ideas of religion which we possess and fully surrender directly unto the Supreme Lord.”
Further reading: Does the Bhagavad Gita Advocate War? Is the central dilemma, to fight or not to?