The classic method of forming alliances by political marriage is well attested in Assyria. And as the following oracle query (PRT 16) shows, these marriages were routinely adorned with a suitable treaty:
"O Šamaš, great Lord, give a firm answer to the question I am asking you: Will Protothyes, king of Scythia, who has now sent his messengers to Esarhaddon, king of Assyria, on account of the king's daughter - if Esarhaddon gives him a princess, will Protothyes speak true and honest words of peace with Esarhaddon, will he keep the treaty (adê) of Esarhaddon, king of Assyria, and do whatever is good to Esarhaddon?"
This marriage certainly looks like a good deal to both parties. To the Scythian king it meant a powerful ally on top of a sizable dowry; to the prospective father-in-law, a cheap and easy way of acquiring control over a dangerous nomad nation looming up within the borders of the empire. Note the end of this quotation and compare it with Text 13 ii 3ff.
To add to the loyalty of his treaty partners, the Assyrian king did not shun assuming the role of a happy bridegroom himself every now and then:
"Mugallu, king of Tabal, who had defied my royal fathers, sent his own daughter with ample dowry to me to Nineveh and kissed my feet. I imposed upon him a yearly tribute of stately horses." (Streck Asb p. 18.)
Simo Parpola
Simo Parpola, 'Alliance Treaties', 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/alliancetreaties/]