Interesting (a word for "I don't know what to do with this information) is the assertion by the Oxford Bible Commentary, on the Apocrypha, that the letter or the previous one to Sparta may not be authentic.
What do we do with the idea that part of Scripture may have been written to make a point about what to do now rather than to report literally what happened then?
But, the commentary goes on to point out that it is interesting that the Jews want to remind Sparta of their common ancestry.
I'm considering how it can still make a difference in choosing allies if we have a prior connection with them, or if we think they are somehow like us.
Jonathan attempted to confirm alliances with the powerful nations, Rome and Sparta.
In a letter to Sparta, he asserted that the Jews had family ties with them, "We therefore remember you constantly at festivals and on other appropriate days, at our sacrifices we offer and in our prayers."
The letter asserted that the Jews when faced by attack from their enemies had not wanted to bother the Spartans and that their victories had come from help from Heaven.
He appended a letter sent to Onias he reminded the Spartans of their common ancestry from Abraham and concluded that they would share ownership of land and livestock.