In response to the question "Why does Bluntschli not want to die in Act 1 of George Bernard Shaw's play The Arms and the Man?", Shaw himself might respond with another question, namely: "Why would any sane man want to die if he could avoid it?" Shaw himself was a pacifist, who published a book Common Sense About the War (1914) strongly opposing World War I and critiquing the militaristic attitude and rhetoric underlying the war. This play, like many of Shaw's works, argues that the romantic ideologies which glorify bravery and death in war are not only false but harmful to both individuals and society as a whole.
Bluntschli is in many ways a mouthpiece for Shaw himself. He is a professional soldier and a realist who carries food rather than ammunition in his pockets, and who is participating in the war because it is his job. The immediate reason that Bluntschli gives for not wanting to die is that it is a bad military tactic, as is seen in this dialogue:
RAINA (disdainfully). I suppose not. (She draws herself up superbly, and looks him straight in the face, saying with emphasis) Some soldiers, I know, are afraid of death.
MAN (with grim goodhumor). All of them, dear lady, all of them, believe me. It is our duty to live as long as we can, and kill as many of the enemy as we can. ...
Beyond this rather pragmatic view of soldiering as a profession, Bluntschli also has no illusions about the romance of war or the nobility of his cause, and thus does not have any motivation to sacrifice his life if he can avoid doing so.