Federalist roads not taken (yet)

Today most of the citizens living in democracies do so in democratic federations: the United States, Canada, Australia, Switzerland, Southafrica, Germany, India... Many live in increasingly federal organizations, such as the European Union. However, some of the key problems of the world may be related to federalist roads not taken by some of the jurisdictions that remain unitary states.
For example, in "Zionism. The Roads not Taken," Noam Pianko explains the intellectual history of ideas in the Zionist movement that did not see state sovereignty and self-determination as the only or best solutions to the Jewish community. Of course this resonates with the idea of the one state solution, which is today unfortunately seen as unrealistic in the Middle East.
Another example comes from the history of China. In a recent paper, the great Japanese economist Masahiko Aoki touches again on the issue of Chinese federalism in the early Twentieth Century, and how the appeals of Chen Jiaming did not succeed in front of the centralist tendencies of the Communists and the Nationalists, although he was later praised by Bertrand Russell or even Mao Zedong. Today, some de facto federalist aspects of the modern Chinese economy ("market preserving federalism") are seen as key aspects of its recent spectacular growth. Others see it necessary for the current Chinese government to reform the state in an openly federalist direction, and as mentioned earlier in this blog, Milanovic believes that if China ever becomes a democracy, it will have to be under a good federal system, to balance the enormous regional disparities that exist there.
Finally, Bates et al. explain how some attempts to build federations larger than the current nation-states in both Africa and Latin America failed in the Ninetieth and Twentieth Centuries, which contributes to explaining the dismal post-independence performance of these regions, as they were unable to consolidate the transnational public goods that were left by the previous empires.
Perhaps today we would be living in a better and more secure world if instead these roads had been taken.