[Kuruharan]

A couple of thoughts…

Next, I would like to tackle the contention that Minas Ithil was a “walled city not a fortress.

The two are not mutually exclusive.

And on the topic of competent rulers, was the Gondorian King at the time of Ithil's fall an intelligent, wise leader or a fool?

The king was Earnil II who was far from incompetent.

The garrison in Minas Ithil may already have been insufficient for an attack of any importance from Mordor: that, too, seems to be implied by the text. Because they could not merely escape but had to hold the city, the Minas Ithil garrison was unlikely to launch a counterattack into the valley against superior numbers, so that the Nazgûl had only to control access to the western end of the narrow pass to prevent relief from arriving from Osgiliath or Minas Anor, and they must have had sufficient forces at their command for this purpose: I estimate that would require no more than 1500-2000 soldiers, and perhaps considerably fewer even than that. (300 Spartans and 700 Thespians held the Pass of Thermopylae against the entire Persian army for three days.) Essentially, the besiegers would have to completely control the western four or five miles of the narrow road, including the approach road to Minas Ithil. Since the line of the attack was long but very narrow, depth in their position made the Nazgûl’s forces strong, particularly if they could rapidly erect barriers to improve their defenses.

While your tactical sense is sound, I must disagree with a few key points. First of all, three days is nothing like two years.

Second, while just for the sake of discussion I’ll go with the idea that the Nazguls’ army outnumbered the defenders (for future reference, a point I am not conceding) I doubt this army could have been strong enough to hold back the might of Gondor indefinitely if it were applied in that situation, certainly not for two years. Even heavily defended places will fall, even if it is costly, to sustained pressure without relief. We are back to the same problem of where was the Nazguls’ army to come from and how was it supplied.

I suspect that most of the foodstuffs required by the attackers for the siege came from Nurn or from eastern Mordor, all of which would reasonably seem to be arable to some extent.

Whether they were arable and whether they were occupied at the time are two different things. Even if they were occupied the occupation was recent and possibly had not reached the self-supporting stage. Military campaigns require large stockpiles of everything. The real problem is where those came from.

The one great advantage that the Dúnedain possessed was their communication by means of the palantíri.

An interesting factor indeed, one that leads me to the conclusions that A) the king and his council must have had some idea of what was going on and B) that they would be willing to pay a pretty heavy price to get the palantir back. I think that if they had believed that a substantial military campaign was in order they would have done it. And Gondor’s power was still sufficient to do this. Remember that the reason why the Witch-king was back in Mordor in the first place was because Gondor had reached up and kicked him out of Angmar. I find it impossible to believe that the Witch-king had an army at Minas Ithil the size of the one he had at Fornost and Gondor was able to crush the Angmarian army from afar.

I believe, given the seemingly conflicting information we possess, something unorthodox happened at Minas Ithil and I think a “haunting” is by far the most reasonable explanation which is in line with what we know. The critical factor in my view is that the Gondorians didn’t understand what was happening and hauntings are good for that sort of thing.