[Raynor]

Originally I was going to post exactly that argument, but it rapidly occurred to me that this is only true when a weaker character on the 'good' side is faced with a more powerful 'evil' character, and in all cases divine providence clearly has a hand.

However, the divine always has a hand, as seen in Manwe's vision from the Silmarillion, or from Tolkien's notes in the Athrabeth. The question is whether this 'hand' significantly reduces, or if it nulifies, the value of the weak's contribution to victory. I hold that it doesn't.

In any case, the unqualified statement that failure will result in no noble or sanctified beings cannot possibly be true: the Valar are sanctified and noble beings, as are the Eldar in Aman.

My position is that in a complete reign of evil there exists no free will, and therefore no ennoblement or sanctification. The same would be true for Arda if evil wins, or for any extent of this hypothetical reign - Ea or beyond it.

Whilst to overturn something is to affect it dramatically, one can affect something dramatically without overturning or defeating it.

I disagree that a policy which is 'dramatically affected' remains the same or can produce the same effects as initially.

The mercy inherent in assistance is earned only by supreme resistance to evil and overwhelming courage

If I understand you correctly, you presume that divine internvetion occurs only when it is earned. I know of no such principle in Tolkien's work. Eru acts according to his own plans; "He will not suffer Himself to be deprived of His own, not by any Enemy, not even by ourselves" (Athrabeth).

my analogy was simply provided to demonstrate how something can be beyond the powers of the weak to defeat (the weak in my example being me and the strong Dover Castle) without being indestructible.

However, this discussion is about confronting another person, not an object. I don't want to venture into other analogies, however possible or impossible they may seem.

I think you'll find me a more reliable source in this instance than Wikipedia.

Wikipedia was not my source, not that it matters. You should look at the very post you yourself linked, since among the meanings appears "great, high courage", "great courage", which is similar to what I quoted, and which refutes your previous statement that "in no way does [ofermode] equate to the Northern ideal of courage, particularly as expounded by JRRT".