Joram went over to Zair - This is the same as Seir, a chief city of Idumea. So Isaiah 21:11 : The burden of Dumah (Idumea). He calleth to me out of Seir.

Smote the Edomites - It appears that the Israelites were surrounded by the Idumeans; and that in the night Joram and his men cut their way through them, and so got every man to his tent, for they were not able to make any farther head against these enemies; and therefore it is said, that Edom revolted from under the hand of Judah unto this day.

Yet. `And so fulfilled'

Genesis 27:40 And by your sword shall you live, and shall serve your brother; and it shall come to pass when you shall have the dominion...

2 Kings 8:20 In his days Edom revolted from under the hand of Judah, and made a king over themselves.

Libnah

2 Kings 19:8 So Rabshakeh returned, and found the king of Assyria warring against Libnah: for he had heard that he was departed from Lachish.

Joshua 21:13 Thus they gave to the children of Aaron the priest Hebron with her suburbs, to be a city of refuge for the slayer...

2 Chronicles 21:10 So the Edomites revolted from under the hand of Judah to this day. The same time also did Libnah revolt from under his hand...

The Assyrian Revival and the Struggle for Syria
Assur-nazir-pal (885-860) and Shalmaneser III. (860-825)--The kingdom of Urartu and its conquering princes: Menuas and Argistis. Assyria was the first to reappear on the scene of action. Less hampered by an ancient past than Egypt and Chaldaea, she was the sooner able to recover her strength after any disastrous crisis, and to assume again the offensive along the whole of her frontier line. Image Drawn by Faucher-Gudin, from a bas-relief at Koyunjik of the time of Sennacherib. The initial cut, …
G. Maspero—History Of Egypt, Chaldaea, Syria, Babylonia, and Assyria, V 7

Kings
The book[1] of Kings is strikingly unlike any modern historical narrative. Its comparative brevity, its curious perspective, and-with some brilliant exceptions--its relative monotony, are obvious to the most cursory perusal, and to understand these things is, in large measure, to understand the book. It covers a period of no less than four centuries. Beginning with the death of David and the accession of Solomon (1 Kings i., ii.) it traverses his reign with considerable fulness (1 Kings iii.-xi.), …
John Edgar McFadyen—Introduction to the Old Testament