What is the thesis and motive is in the following introductory paragraph:

"Thucydides states that at the beginning of the Peloponnesian War, the Spartans consulted the Oracle of Delphi to determine whether or not they should go to war with Athens. The answer given to them was that if they fought with all their strength, they would achieve victory, and the god himself would be on their side, whether they invoked him or not. Sparta then called together their allies at Corinth, and, owing in part to the oracle's sanction, Sparta's hesitation was overcome and the League decided to go to war.This episode illustrates the role of the divine in diplomacy between Greek poleis. Divine approval was a key factor in many areas of Greek life, especially in military and political issues. The approval of the Delphic oracle was greatly valued and its advice was often requested by Greek states. However, the oracle's response that Thucydides mentions also demonstrates a problem. The sanctuary was supposed to be neutral in political struggles between Greek cities, yet Delphi's blank check of support to Sparta for waging war against Athens was not the first or the last time in which the oracle seems to have taken sides. Delphi was overseen by a council of representatives, the Delphic Amphictyony, with members from central, northern, and southern Greece, and if the oracle was seen to be partisan, this would surely have diminished its authority. At the same time, Delphi had its own stake in the political struggles of Greece and an interest in remaining on good terms with the powerful.

This paper explores the role that the oracle played in wars between Greek cities from the Archaic Period to the rise of Macedon, and in particular examines in what circumstances the sanctuary took sides and how it managed the conflicts of interest it faced. Although it is true that the oracle often gave support to the most powerful Greek cities, I argue that the oracle's support for any one city was neither constant nor without condition. Powerful Greek cities helped maintain Delphi's fame, wealth, and security, while Delphi in turn could lend weight to a city's standing. Rather than simply ally itself to power, however, Delphi managed a delicate balancing act, having at the same time to burnish its Panhellenic credentials. Although in a delicate position, Delphi survived the wars of this period and remained an oracle for all the Greeks."