In Act 1 of Arms and the Man, the subject of war is mainly portrayed through the perspectives of Raina and Captain Bluntschli.
While Raina is enthralled with the idealized notion of the war hero, Captain Bluntschli is more honest about the realities of war. At the beginning of Act 1, Raina is ecstatic with the news that her fiance, Sergius Saranoff, has distinguished himself as the hero of the hour. He has supposedly defied the Russian commanders and led an independent Bulgarian charge against their collective Serbian enemies. Sergius is everything Raina worships in a war hero: he is good-looking, wealthy, well-pedigreed, chivalrous, and fashionably brave. Although she initially doubts his warrior ethos, lamenting that she reads too much Pushkin and Byron, this fantastic news of her fiancé's courage bolsters her spirits.
On the other hand, Captain Bluntschli is disturbingly honest. He starts to divest Raina of her preconceived notions about soldiers almost immediately, telling her that "nine soldiers out of ten are born fools." The captain is a cynic; he is a professional Swedish soldier-for-hire who only joins the Serbian side because it is nearer to his homeland. He eats the sweets Raina offers him with an almost child-like glee and grateful appreciation. Spontaneously, he admits to Raina that he has been under fire for three days and that he is as nervous as a mouse. Ever the realist, he then proceeds to divest Raina of her perceptions regarding her fiancé's war bravery.
It turns out that Sergius Saranoff had actually led a cavalry charge against an enemy arrayed with an impressive battery of machine guns. If it hadn't been for the fact that Captain Bluntschli's side had blundered by equipping the Serbians with the wrong cartridges, Sergius might not have lived to boast about his comically ill-conceived charge. Captain Bluntschli is extremely amused when he discovers that Sergius is Raina's fiancé; with the air of an experienced soldier, he reminds Raina that the older soldiers often carry food, while the younger soldiers (their heads filled with idealistic notions of the glories of battle) often pack just ammunition and cartridges.
Captain Bluntschli also betrays his humanity when, at the end of Act 1, he sinks onto Raina's bed into an exhausted sleep. War is hard, exhausting work, its reality far from the romantic portrayals of battlefield glory and valor.