could any of the kingdoms at middle earth attack the southern continents?

[Morthoron]

Originally Posted by tom the eldest

This is about the probability of middle-earth's forces to attack the dark lands.i mean,the logistics,the amount of troops,the distance,etc.the south continent do have mumakil,and the kingdom there probably have lots and lots of troops,like most primitive tribes of africa.

Tolkien does not provide enough information. From an historical perspective, lands are conquered so that natural resources can be exploited: whether that means fertile land to feed an expanding population; the availability of rich lodes of precious metal, iron ore or coal; some other tangible and tradeable goods (like rare spices, as someone mentioned); or sometimes the people of a certain region are exploitable goods for the slave trade.

We don't know. It is all conjecture. There is no mention of it. There are only possibilities based on real-world historic data.