How would history change if Wilhelm II became both Kaiser of Germany and Tsar of Russia in 1901?
Short answerIt would create an enormous German-Russian bloc dominating the Baltic, alarming every major power, suppressing revolution more effectively, and forcing Britain toward tighter imperial coordination.
NotesIn this counterfactual, France would lose the Russian counterweight to Germany, while Britain and Japan would confront a much larger Eurasian bloc. German troops could reinforce Wilhelm's position in Russia, and Russian troops could support him in Germany, making revolution less likely. Combining the two countries' Baltic coastlines would give the union a dominant position in that sea. Russian ambitions toward Constantinople would gain German backing, while port access and railway construction would draw on the combined resources. Integration could take about a decade, but rivals would hesitate to start a preventive war against the bloc. Hostile Habsburg treatment of an heir's wife and children might even let Wilhelm present himself as an alternative successor and bring Austria-Hungary into the union. Poland would sit inside the combined empire with little chance of independence. The threat could push Britain toward greater imperial cost sharing and perhaps a federated empire instead of the later Commonwealth path.