Here’s my stab at it, Bill:

Why should I place the blame for my misery on her, (L1-2)
or blame her for the drive to violence she inspires
in men who are less wise than she (L2-3)
(or anyone with courage equal to their passion), creating war
between the underdogs and the masters? (L4-5)
After all, how could she be expected to be peaceful,
With a mind that nobility focused to an elemental force (L6-7)
And possessed of deadly unnatural beauty
that sets her apart from all others in this age, (L8-9)
since she is above us all like a judgment of god? (L10)
So being what she is, how could the outcome have been
any different than this destiny, the burning of Troy? (L11-12)

Even not knowing the biographical background, I can respond to the wonderful imagery of this poem – “beauty like a tightened bow”, “hurled the little streets..”, “a mind….as a fire”. And this last I would see as the central image, of a force that can translate into actions causing “another Troy to burn”. The apostrophic form of the poem makes it clear the poet feels the course of events was preordained, a grievous calamity falling as the inevitable outcome of a collision between this godlike creature and a mundane world. I love the way Yeats packs his complex imagery within the tight sonnet structure – it responds to careful reading as a result.