I recently read in Wikipedia that the figure Tanit was "identified" with another deity Astarte, whom the Carthaginians inherited from Phoenician religion, therefore I wonder was she an adaptation of Astarte/Ashtart (or perhaps the same deity worshipped in another name and possessed different attributes after centuries) who was herself a form of the Mesopotamian deity Inanna/Ishtar?
Also, Inanna was portrayed as having both solar and lunar aspects, which led me to the conclusion that Carthaginians split the deity's character into two, and apparently their religious system was influenced by eastern Semitic culture or something more ancient such as Sumerian texts...while on the other hand, could it be that Astarte had solar aspects within Canaanite beliefs as well?
Note: I've been posting these sorts of question here mainly because Wikipedia and other sites simply lack the answers I'm searching for, they're mostly...too vague regarding texts.
I don't think it is very a very fruitful line of inquiry to pursue "Carthaginian Tanit = ______ in the East." As the evidence sits right now, Tanit does not seem very similar to any deity of the Near East. She shares certain aspects with other Semitic deities through time, but what is going on with Tanit at Carthage seems wholly unique to the Carthage (and from there the Western Med). That is not to say that our understanding is perfect: Western Phoenician sites like at Carthage, Motya, the Sardinian cities, and the enclaves on the Costa del Sol have been excavated by modern, meticulous (often German) teams. The Phoenician homeland, meanwhile, is a very difficult place to do archaeology, especially in modern times.
There is also what I think is a basic, erroneous assumption among many scholars: that the Phoenicians in the West, especially those who remained beyond the initial first-generation phase of the late-8th to early-7th centuries BCE, understood and continued their "religion" in the same way as the Phoenicians of the homeland cities at Tyre and Sidon had done. We see a lot of apparent "mixing" in the imagery of the West, with the blending of iconic and aniconic features into divine amalgamations. Tanit is a great example, I think. The whys of that are not yet established, but the desire to "break away" from the mother cities back home could certainly be a factor. The western cities, especially Carthage, certainly did "break away" beginning as early as the first quarter of the 7th century.
I am by no means an expert on Near Eastern mythology, but I find the connection between Tanit and Astarte to be incredibly weak. The Greeks, who had much more access than we do, always equated Astarte to Aphrodite. Carthaginian Tanit, from what little we know, was a ruler's consort, a force of jealousy and retribution and anger, and a meddler in the domains of others, especially the weather of the seas. At Carthage, she seems to be as much a Sea Goddess as anything else, child sacrifice aside. The Romans then naturally understood Tanit to be Juno, who also embodied all these traits. In particular, they called her Juno Caelestis, perhaps on analogy with their understanding of Baal Hammon as "Saturn."
There is a newish monograph related to this topic which I have not looked at, but might be good: Doak, Phoenician Aniconism in its Mediterranean and Ancient Near Eastern Contexts (Atlanta: SBL, 2015). From a quick skim, I can see that he talks about the evidence (or lack) for Tanit in new excavations at Tyre.