some strong points above!
1) Jews did not return to EY by force, this was immigration over decades, mostly with permission of the current authorities, and without weapons. Neighboring Arabs were not an authority, Brits under UN mandate were, thus UN vote seems like an authoritative call. As Avira says, when other countries attacked, self-defense seems legit
2) a letter to Teiman not making it into codices. How often do we have issues of such importance not making it into halakhic books? do we have examples?