Prussia is built for a genuinely hostile, isolated diplomatic stance — its military gets stronger the worse your relationships are with everyone else, and it can keep trading with civilizations it's actively at war with.
"Blood and Iron" grants units increased Combat Strength for every Unfriendly-or-worse Relationship you have with other civilizations — a direct reward for a confrontational diplomatic posture rather than a penalty for it. Later tiers add a Production adjacency for Navigable Rivers on all Buildings, increased Science from Resources, and the ability to establish and maintain Trade Routes with cities you're currently at war with.
Details on Prussia's specific unique units were not part of the source material verified for this page — flagged for a follow-up pass against the official Civilopedia or game guide.
Details on Prussia's specific unique buildings and associated Wonder were not part of the source material verified for this page — flagged for a follow-up pass against the official Civilopedia or game guide.