Izetta is powerful enough to fight whole armies, but her strength is limited.  She can only use her abilities near certain ley lines, and outside them, she's no different than a normal girl. When the Germanian army attacks in a spot far from these ley lines, the duchy is forced into a corner: how can they repel these foes without giving up the secret of Izetta's strength?
Given what Captain Basler said,
،بحسبِ ما قالَه النّقيب باسلر
Hauptmann Baslers Aussage nach zu urteilen
ist die Hexe ziemlich unbesiegbar, oder?
Con lo que dijo el capitán Basler,
Con lo que dijo el capitán Basler,
Doit-on déduire de son histoire
qu’elle est bien invincible ?
Dalla storia del capitano Basler
Pelo que o capitão Basler disse,