It was the strength forged in fighting his personal Black Dog, that Churchill lent to us when we most needed it. And the poem he quotes in this broadcast has that mingling of suffering, determination and joyous tears. I give Clough's text in full after the link.
Churchill's War Time Speeches.
A Difficult Time.
'Westward, Look, the Land is Bright'
27th April 1941
Say not the Struggle Naught availeth
SAY not the struggle naught availeth,
The labour and the wounds are vain,
The enemy faints not, nor faileth,
And as things have been they remain.
If hopes were dupes, fears may be liars;
It may be, in yon smoke conceal'd,
Your comrades chase e'en now the fliers,
And, but for you, possess the field.
For while the tired waves, vainly breaking,
Seem here no painful inch to gain,
Far back, through creeks and inlets making,
Comes silent, flooding in, the main.
And not by eastern windows only,
When daylight comes, comes in the light;
In front the sun climbs slow, how slowly!
But westward, look, the land is bright!
Arthur Hugh Clough