[LotR] Route of the Haradrim?

[Rogue 9]

I was bored at work last night, so my mind started engaging in a massive free association exercise, as it tends to do when bored. Anyway, one of the results of this was that my train of thought randomly arrived at thinking about the route the Haradrim took when they were traveling to Mordor in The Lord of the Rings. My question is this: Why go all the way around to the Morannon when they could simply go a little to the east and travel through Nurn? I should think it would work out much better for them to move through Mordor's breadbasket unmolested than to travel through Ithilien (harassed by the rangers of Gondor) all the way around to the Black Gate, to then camp out on the blasted plains of Gorgoroth.

[Rogue 9]

Oops, wrong forum. Meant to put this in Fantasy. Could a mod kindly move it, please?

[Jericho Kross]

A few problems with going through nurnen may have been: a) not many bridges that allow the Haradrim and Mumikil to get past nurnen and the rivers in southern Mordor, b) the climate is very harsh and they would taken many casualities by taking this route[unknown to them that the rangers would ambush them], or c) Sauron had a certain reason to have them go this way.

[Rogue 9]

The climate is harsher in the slave farms than on the volcano-blasted plateau they were expected to camp out on? Huh?

[Jericho Kross]

It is possible that the dessert route[eastern Harad] was something like the sahara desert and would have been a risk taking heavy losses from the intense heat.

[Jericho Kross]

After rewhatching the Two towers, another reason they may have taken the path through Ithilien is because the amount of food present for themselves and thier mumikil[they had long wanted the fertile lands to the west most likely for this reason].