Although Azerbaijan, a Shiite-majority nation in the Caucasus, does not maintain an embassy in Israel, it has a strong alliance with the Jewish state, importing Israeli military technology and exporting oil. Israel also seems to use Azerbaijan for intelligence-gathering, in exchange for advice and training for the Azeri military. But the relationship runs deeper than that, as Gallia Lindenstrauss writes, as the two countries share an enduring interest in checking Iranian aggression:
[D]uring the [1991-1994 Armenian-Azerbaijani] war over Nagorno-Karabakh and the nearby areas, Iran was (and still is) an ally of Armenia. Another source of dispute between Azerbaijan and Iran is the division of natural resources in the Caspian Sea, and in addition the Azerbaijanis accuse Iran of encouraging a religious revival among their Shiite population. . . .
While many countries perceive Iran, and especially its nuclear program, as a threat, most do not regard it as an existential threat; the few countries that do, include both Israel and Azerbaijan. . . . [I]n many respects, Azerbaijan is irreplaceable for Israel, and the proximity of this country to Iran makes it especially attractive.
Read more on Institute for National Security Studies: http://www.inss.org.il/uploadImages/systemFiles/adkan17_4ENG_7_Lindenstrauss.pdf