Wilfred Owen's poem "Strange Meeting" shares some interesting thematic and descriptive similarities with a much shorter, earlier poem by Siegfried Sassoon entitled "Enemies" (probably inspired by the death of Sassoon's close friend and fellow officer, David Thomas -- see also Robert Graves, another close friend of David Thomas, and Graves' poem "Goliath and David").
Enemies

He stood alone in some queer sunless place
Where Armegedoon ends. Perhaps he longed
For days he might have lived; but his young face
Gazed forth untroubled: and suddenly there thronged
Round him the hulking Germans that I shot
When for his death my brooding rage was hot.

He stared at them, half-wondering; and then
They told him how I'd killed them for his sake --
Those pateint, stupid, sullen ghosts of men;
And still there seemed no answer he could make.
At last he turned and smiled. One took his hand
Because his face could make them understand.

6 January 1917
Siegfried Sassoon (1886-1967)

Strange Meeting

It seemed that out of battle I escaped
Down some profound dull tunnel, long since scooped
Through granites which titanic wars had groined.

Yet also there encumbered sleepers groaned,
Too fast in thought or death to be bestirred.
Then, as I probed them, one sprang up, and stared
With piteous recognition in fixed eyes,
Lifting distressful hands, as if to bless.
And by his smile, I knew that sullen hall,--
By his dead smile I knew we stood in Hell.

With a thousand pains that vision's face was grained;
Yet no blood reached there from the upper ground,
And no guns thumped, or down the flues made moan.
'Strange friend,' I said, 'here is no cause to mourn.'
'None,' said that other, 'save the undone years,
The hopelessness. Whatever hope is yours,
Was my life also; I went hunting wild
After the wildest beauty in the world,
Which lies not calm in eyes, or braided hair,
But mocks the steady running of the hour,
And if it grieves, grieves richlier than here.
For by my glee might many men have laughed,
And of my weeping something had been left,
Which must die now. I mean the truth untold,
The pity of war, the pity war distilled.
Now men will go content with what we spoiled,
Or, discontent, boil bloody and be spilled.
They will be swift with swiftness of the tigress.
None will break ranks, though nations trek from progress.
Courage was mine, and I had mystery,
Wisdom was mine, and I had mastery:
To miss the march of this retreating world
Into vain citadels that are not walled.
Then, when much blood had clogged their chariot-wheels,
I would go up and wash them from sweet wells,
Even with truths that lie too deep for taint.
I would have poured my spirit without stint
But not through wounds; not on the cess of war.
Foreheads of men have bled where no wounds were.

'I am the enemy you killed, my friend.
I knew you in this dark: for so you frowned
Yesterday through me as you jabbed and killed.
I parried; but my hands were loath and cold.
Let us sleep now. . . .'

Wilfred Owen (1893-1918)