Manga Like Ashita no Teki to Kyou no Akushu wo

The Dragonfly Empire is tearing itself apart from the inside. The nation is deeply divided between two groups: the "Fleet Faction," which advocates for joining the world-conquering Imperial Alliance, and the "Treaty Faction," which insists on maintaining friendly ties with the Entente to preserve the global status quo. Just as the political pressure to join the Imperial Alliance and not get left behind reaches a boiling point, a massive aerial battle over Jutland drastically shifts the tides of war. In the aftermath, newly commissioned Lieutenant Amelia is deployed to the increasingly hostile Entente nation of Britannique as a military attaché. Accompanying her is Vice Admiral Harald of the Treaty Faction, a man notorious for being a monster of pure logic. One wrong move means a world war. Utilizing their government, the embassy, the nobility, and the media, they must fight a hidden battle to ensure that heroes will never be needed. (Source: Akita Shoten, translated)