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?
That whole thing was a setup.
كان ذلك الشيء برمّته مجرَّد تخطيط
Die ganze Nummer
war wohl im Voraus geplant,
Todo eso fue un engaño.
Todo eso fue un engaño.
Le terrain avait l’air préparé…
Tu t’es servi de la garde ducale ?
Mi sembra che tu abbia 
preventivamente approntato diversi trucchi.
Tudo aquilo foi armado.