What are the contributions of political thought to political development?

This is a fascinating question, especially when one views the history of political philosophy in the context of the political systems that prevailed during the exact time that varying philosophies were being put forward.

For example in ancient China, the political philosophy of Confucius was generally thought to be in support of the imperial rule extant during the fifth century B.C. (though many factions throughout China vied for power, and warfare was a constant during his...

This is a fascinating question, especially when one views the history of political philosophy in the context of the political systems that prevailed during the exact time that varying philosophies were being put forward.

For example in ancient China, the political philosophy of Confucius was generally thought to be in support of the imperial rule extant during the fifth century B.C. (though many factions throughout China vied for power, and warfare was a constant during his lifetime). Confucius advocated for placing the most moral and conscientious rulers in positions of power, from emperors on down to court officials, regional authorities, local authorities, bureaucrats, religious officials, etc. He counseled all members of society, be they children in relation to their parents or peasants in relation to their landlords, to conduct themselves with respect and courtesy (this was meant to cut both ways). He advocated for correct behavior, correct language, correct social manners, politeness, and a profound sense that all people and all institutions have the good of all people in mind when conducting one's affairs. His ideas were actually officially promulgated a few centuries after his death by China's emperors.

The ancient Greek political philosophers are famous for their advocacy of various political systems, ranging from outright tyranny to the more liberal forms of democracy (as limited as democracy was to free Greeks). Plato, for one, advocated for rule by a very limited cadre of supremely trained and educated elites who disavowed the lives of acquisition or for the exercise of mere power, arguing that only rulers steeped in the severe discipline of divining the key to making all sectors of society work in concert for the good of the nation were qualified to rule. Various city-states did indeed adopt the various political philosophies of Greece's greatest theorists, with much of the Western world indebted to the development of political thought created thousands of years ago.