Simcha613: I’m not well versed in Na”ch either, so I can’t say if the Kingdom of Malchus Yisroel was sanctioned by Hashem or not. However, definitely later during Bais Sheini in the times of the King Hurdus, Chaz”al were in alliance with the King and prayed for his welfare, even though his rule was not sanctioned by Hashem; as stated in the Gemara with the story of Buva Ben Buta who refused to curse the king even after he had killed many sages (a far cry from the democratic state of Israel!), and then the Chachamim advised him to rebuild the Bais Hamikdash.
Also during the times of Bar Kochba’s revolt, although the majority of the army and Bar Kochba himself were not religious, still the sages aligned themselves with them and prayed for their success, as mentioned in the Gemara about Rabbi Akiva and in the Midrash about Rabbi Eliezer Ben ? who actually was together with Bar Kochba during the siege, and prayed each day for the survival of the army and the Jews.