In what ways is war romanticized in Arms and the Man?

The main aim of George Bernard Shaw in his play Arms and the Man is to debunk the romantic image of war; as a playwright, Shaw deromanticizes war by mocking or undermining characters who have the unrealistic view that war is glamorous.

While Shaw himself does not consider war romantic, several of the characters in the play do start out with that position, although the events of the play and Captain Bluntschli's arguments eventually move both the characters and the audience to a more realistic view. 

Raina originally has a glamorous ideal of war based on a combination of epic and romantic poetry. She projects this ideal onto Sergius, who himself is caught up in the problem of trying to live up to the mythos of the war hero. 

The difference between the practical approach to war of mercenaries and the romanticism of amateurs is seen in Bluntschli's description of Sergius' charge:

He did it like an operatic tenor—a regular handsome fellow, with flashing eyes and lovely moustache, shouting a war-cry and charging like Don Quixote at the windmills. We nearly burst with laughter at him; ...