ps - the dropping of 'Om'
It would indicate the apprehension that contemporary social ambience is too secular to listen to any articulation of mystic faith -- that it would at best be dubbed "mad".
Nevertheless, equipped with true knowledge and experience acquired vis-a-vis the wasteland,
                              I sat upon the shore
Fishing, with the arid plain behind me
Shall I at least set my lands in order?
The poem looks forward with resolution and hope to a lasting peace.
Datta. Dayadhvam. Damyata.
     Shantih  shantih shantih

From: Chokh Raj <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, September 12, 2011 10:50 PM
Subject: Re: Eliot vis-a-vis the mystic 3

some more thought
I was just exploring why Eliot chose to drop the initial "Om" from the closing incantation of TWL. 
Well, the reason could simply be prosodic -- the poet would be governed by his new requirements of rhythm.
He would also quite obviously find the triple incantation "Shantih shantih shantih" quite apposite beside the preceding three-fold mantra "Datta. Dayadhvam. Damayata". 
He would, of course, uphold tradition without sounding too pedantic.
Above all, Eliot has his own manner of borrowing material. He borrows in snatches -- suggestive, terse, parts standing for wholes.
I'm not sure Eliot dropped "Om" (the logos of revealed truth) to suggest the poem had not reached a point of full illumination -- a view advanced by Cleo McNelly Kearns ('T.S. Eliot and Indic Traditions: A Study of Poetry and Belief', 1987).  It could albeit suggest the wastelanders are not yet ready for the grace of mystic light. The poet, therefore, makes his prayer for peace in terms that might carry conviction with them. 

From: Chokh Raj <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, September 12, 2011 3:06 PM
Subject: Re: Eliot vis-a-vis the mystic 3

Om     Shantih     shantih     shantih
----------Shantih-----shantih-----shantih   [the spaces as in the text]
I was just measuring the space Eliot left before and in the course of each incantation.

From: Chokh Raj <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, September 12, 2011 12:09 PM
Subject: Re: Eliot vis-a-vis the mystic 3

'The Word without a word'
Reminds me of the Greek Logos in 'Mr Eliot's Sunday Morning Service'.
"In the beginning was the Word, and the Word was with God, and the Word was God" (John i, I). 
"The word within a word, unable to speak a word, 
 Swaddled with darkness."
   -- 'Gerontion'

"If the lost word is lost, if the spent word is spent
 If the unheard, unspoken
 Word is unspoken, unheard;
 Still is the unspoken word, the Word unheard,
 The Word without a word, the Word within
 The world and for the world;
 And the light shone in darkness and
 Against the Word the unstilled world still whirled
 About the centre of the silent Word."
   -- 'Ash-Wednesday'
a perspective, if you like

From: Chokh Raj <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, September 12, 2011 10:02 AM
Subject: Eliot vis-a-vis the mystic 3

À la Dante, Eliot must have been intrigued by the mystic 3.
"Here is the man with three staves"  
London Bridge is falling down falling down falling down  
Poi s’ascose nel foco che gli affina  
Quando fiam ceu chelidon—O swallow swallow  
Le Prince d’Aquitaine à la tour abolie  
These fragments I have shored against my ruins 
Why then Ile fit you. Hieronymo’s mad againe.  
Datta. Dayadhvam. Damyata.   
      Shantih    shantih    shantih
Then at dawn we came down to a temperate valley,
Wet, below the snow line, smelling of vegetation;
With a running stream and a water mill beating the darkness,
And three trees on the low sky,
And an old white horse galloped away in the meadow.
In Hindu belief, the mystic 3 represents "Om", an emblem of cosmic spirit which in its formless aspect is the cosmic space which is all-pervasive -- there is nothing that is not subsumed in it. And now a piece of sheer whimsy. Eliot ends TWL with the Upanishadic incantation of "Shantih", leaving an all-too-conspicuous space before it. This could be deliberate, tacitly assuming an "Om" there -- so that those who know will know. 
BTW, Eliot's use of 3, somehow, always reminds me of Coleridge's vision of a poet in "Kubla Khan":
"Weave a circle round him thrice,
 And close your eyes with holy dread,
 For he on honey-dew hath fed
 And drunk the milk of Paradise."
According to Grover Smith, Eliot admitted to being temperamentally a romantic, and only 'in tendency' a classicist.
He abhorred the gap, writes Smith, between the actual and the ideal.