Theoden's selective outrage
 

After the Ents demolished Isengard, Theoden had a real rant at Saruman during the Orthanc encounter. He castigated Saruman over the dead children in the Westfold and the mutilation of Hama's body at the Hornburg.

But surely uppermost in Theoden's mind at that time would have been the death of his only son, Theodred, at the 1st Battle of the Fords of Isen ? Why didn't he have a go at Saruman about that ?

Perhaps, since Théoden was not a personal witness to the death of Théodred at the Fords of Isen, and he had so lately witnessed the atrocities of Saruman's troops in the Westfold and at Helm's Deep, it was the latter events that stood the clearest in his mind at the time of his encounter with Saruman.
Théodred's death could well have been one of the factors leading to his rejection of Saruman, though.

I'd say this is a likely reason. But also was Theodred's body mutilated upon his death? Anyone would be outraged at the death of children. And Theoden rages about Hama's mutilation more than his death alone. If Theodred was killed and his body not tampered with maybe Theoden viewed this as a far more honorable way for his son to die.
Of course it is surprising he would have nothing to say about his only child's death...

According to the UT section The Battles of the Fords of Isen, Théodred's body was not dishonoured, and his end was valiant. He fell while defending the Fords, and his last words were 'Let me lie here--to keep the Fords till Éomer comes!'

Also, Theoden is acting in full righteous indignation Kingly Capacity here. To bring up something so terribly personal might lead to a loss of dignity.

Though Theodred was his heir as well...

That's what I thought too. He was perhaps taking upon himself the role of speaker for the whole nation, a honorable one, not just for his own personal damage (even though - well, depending how exactly it was considered in Rohan - often whatever happened to King or his family was considered in many cultures the same as if it happened to the whole nation). Háma doesn't quite fit into the picture, though, because it sounds like that here Théoden would still be angry (he had had long time to mourn over his son's death, so he could have been okay with that, but Háma's death as a loyal and close servant was perhaps far too recent) and bringing in kind of more individual matters. Though maybe he was just sort of "reminding" the soldiers next to him, who have known Háma, so this was actually not speaking to Saruman, but more to the soldiers (especially face to Saruman's voice - that actually sounds likely to me, Théoden was just "countering" the Voice about himself and wanted to make sure that even his men see the whole truth clearly).

I wonder just how much Theodred's death truly HAS registered with Theoden at this point. He was still very much under Saruman/Wormtongue's influence at the time it happened, and so much has occurred since his healing, he may not have had the time to fully process this as reality. If he had allowed the grief to hit him as it normally would after Gandalf healed him, it might have rendered him unfit to lead his people into the battle that was already upon them. So, like many in leadership positions, he may have pushed that tremendous grief aside until he has the time and the luxury to let himself feel it fully. If he even mentions it on the steps of Orthanc, he risks breaking down and giving into grief, and that is something he does not dare do. In my opinion, of course. :)

I think there are several issues - Theodred had died a glorious death in the eyes his people and if we assume that Eomer's words at Pellennor "Mourn not overmuch! Mighty was the fallen, meet was his ending. When his mound is raised, women then shall weep.War now calls us" was not uncharacteristic of his people then it isn't that they don't care but that they get on and do what has to be done before they "indulge" their grief.

I do think that Theoden's words at Meduseld are as much for Theodred as his exact contemporary Boromir who died within hours of him "The young perish and the old linger withering". He is also reluctant to pass by the Fords of Isen on the way to Orthanc. I think partly that the death of Theodred is too painful to speak of for Theoden - Eomer speaks of him so he is not forgotten.

However in times of war when everyone has lost people it is not appropriate to make his reasoning so personal. For example in Britain the elaborate funeral and mourning rituals left over from Victorian days disappeared during the First World War because so many had died; most of the dead were buried where they fell so mourning became a private thing, not a public ritual on an individual level which was replaced to an extent by the communal acts of remembrance such as the war memorials that stand in even the tiniest village to honour the dead and comfort those who might never be able to visit actual graves.

At Isengard, everyone there knows what Theoden's greatest grief must be, so when he speaks of other losses the memory unspoken gives power to his words. It is not a politician's pat response but one speaking who knows, only ten days after his son. A very brief time. Saruman has made out that the conflict is a sort of misunderstanding due to Theoden being beset by "unwise and evil counsels" and reproaches Theoden for the injuries done to him! It would have been easy to say "But you murdered my son" but for all that he was targeted, Theodred was a great warrior and died a warrior's death. Mutilating the dead and killing children are war crimes and show that the conflict is deeper and nastier than some sort of border skirmish. Tolkien's heros play it straight - one of the reasons why of all the film's trangressions, Aragorn's killing the emissary of Sauron illustrated just how little Jackson understood the book.

That's a good point. Théoden's lack of tunnel-vision where his son was concerned also probably was a source of comfort to the rank-and-file soldiers, especially those of Westfold, who may have suffered terrible personal losses themselves. If the King could control his grief and fear for the time being, so could they.

Hello,nice story.