We thus see that treaties performed several centrally important functions in Assyrian imperialistic policy:
They were the very means of enlarging the empire, binding new acquisitions to it permanently, regulating international trade, channeling a flow of goods and raw materials to the centre of the empire, adding to the imperial army, tying the hands of enemy powers, and securing the safety of the king and the transfer of power to a successor of the emperor's own choice. In short, they were the very thing that made the Assyrian empire an empire. From the systematic and routine way in which they were used in daily politics it is clear that they were part of a sophisticated and well-tested strategy designed to bring ever new nations under the sway of the Assyrian emperor. Naturally, they could not have had their desired impact without the backing of a strong army, and a willingness to use it ruthlessly and unhesitatingly, but their central role in the imperial policies shows that Assyria was something more than just the crude military power which it is pictured as in the schoolbooks.
It was above all a true superpower making use of all the classic means of political manipulation in its dealings with other nations. It concluded mutual friendship and assistance pacts, only to later invade the county by invitation; it sold arms and military assistance to shaky governments, only to add them to its sphere of influence; it acquired zones of satellites by methodically installing its puppets in exposed countries. These methods sound so familiar that the Assyrians might well have written the modern textbook for territorial expansion by diplomatic means.
Simo Parpola
Simo Parpola, 'Power Politics', Neo-Assyrian Treaties and Loyalty Oaths, SAA 2. Original publication: Helsinki, Helsinki University Press, 1988; online contents: SAAo/SAA02 Project, a sub-project of MOCCI, 2020 [http://oracc.org/saao/saa02/treatiesasinstrumentsofimperialism/powerpolitics/]