Answer:
Greater involvement of the United States in international affairs.
Although this is somewhat subjective, many would agree that the British were the most successful since they developed the colonies such as Virginia that had the highest GDP and export numbers.
On May 22, 1939, Germany and Italy signed the so-called Pact of Steel, formalizing the Axis alliance with military provisions. Finally, on September 27, 1940, Germany, Italy, and Japan signed the Tripartite Pact, which became known as the Axis alliance.
Plato was probably talking about a Democratic government which is composed of several leaders that are in-charge of particular cities and communities in a country. During his time, Plato is a known philosopher who spent his time discussing with people in plazas and squares arguing about almost anything under the sun.