An early Commonwealth as a global economic and defence bloc

How might the world change if an early British Commonwealth project fully succeeded?

It could become a worldwide free-trade, economic, and defence bloc resembling a global European Union and predating the United Nations.

The question imagines British plans for transforming empire into a Commonwealth succeeding from the late nineteenth century onward. The resulting structure could resemble a European Union spread across the world. Its practical core would be a free-trade area, an economic bloc, and a shared defence system rather than a single centrally governed state. Because it would predate the United Nations, such a federation could exert major influence over the institutions and alignments of twentieth-century world politics.