Accidental Allusion

Until within without upon
Goes the sixth grade story
About a pre-position
Before we knew where we were

We held our own hands
And recited lines 
Meant to guard
Homes from land
And ownership
From any mortal enemy

That's the prelude to murder
As the soldier knows
Wartime is a result
Of power forgetting to check its watch

And we are here for it
If we learned well
Aced our precursors
And drew our answers 
Into functional bubbles

Don't guess C
It might be A
And D withholds 
The way to B