The first chapter is called the Yoga of Arjuna's Despondency. It is the canvas on which the entire Gita is painted.
The Mahabharata war was perhaps the war to end all wars. It was bigger in its impact on Indian civilisation than the world wars impacted all of us in the 20th century. Almost every king and army in the subcontinent was there fighting for one side or the other, a mega-war between cousins-extremely powerful men who had grown up in rivalry. One side was clearly evil from the beginning, out to destroy their fatherless cousins, the five Pandava brothers constantly busy in fighting for their very survival amidst all the evil machinations. Humiliated, banished to the forest, and then being denied even a small patch of land, the good brothers had to undertake the war to claim their due from their evil cousins.
Interestingly, even the evil ones believe this is a righteous war for them! ( dharmakshetre kurukshetre).
The paradigm of war is predicated on death. Kill or be killed. All those who celebrate war heroes celebrate the human act of inflicting death or dying for a "cause". Man's ideas of a noble cause involve rights and entitlements, and acquisitions. Might is right. Just like how tigers and lions mark territory and kill mercilessly.
The hero of this warmongering attitude is Duryodhana. He says everyone is there to die for him. He demonstrates the ultimate appetite for war, as killing is fully justified for him to achieve his ends - he wants to finish off his cousins and their claims to the kingdom. He seems afraid of only Bheema among the Pandavas, who has sworn to kill him and his 99 brothers for all their evil deeds.
So other's death as a means to one's victory is the key theme in the first chapter. In a simple way, Gita shows us that the way we relate to death is with this attitude of "Us" versus "Them". As long as "we"can live, by killing "them", it is victory of life over death.
Arjuna has a different definition of "Us". Note he is not against war, but doesn't want to kill his own brethren, teachers and forefathers. He says this war is sinful and meaningless because it entails killing one's own. Not very different from a warmonger, who wants to kill "them", except that Arjuna has a different definition of "Us".
So essentially, death is depicted in the first chapter as a conscious choice for man to inflict on others for his own ends. It is the ultimate step, when all else fails. So we see death here as a kind of murder.
