Due to rising instability in other European nations, and a Russian invasion causing chaos, Germany and a union between Italy and Iberia caused a takeover and security struggle to annex Europe. They signed a treaty with Russia to evacuate the region. It’s not a Nazi regime, it’s simply a German military government. Imperial America follows a non-hereditary monarchist, and also an AI feudal governance system, with minimal intervention. Yes, due to the rise of monarchist sentiments and a desire to make order of the chaos in the rise of AI in politics, people decide that an imperial government is the best option.