Oh How It Grows Weary

This was fairly nice, but not perfect. Okay, review time.

The extension of his arm split the air in two,
filling itself with a lot less than that of pride. (What is the "that" referring to? There is no clear or apparent object/action/etc. in the previous line that might be "that.")
The command to fall strikes the heart of a few, (Changed to a comma because the next line is just a fragment otherwise, and I believe you meant this as a joined whole.)
as widows gaze on the cliff and beyond the tide.
Oh how it grows weary.

Laying Lying on the ground, hidden within the soil (Common mistake, no worries.)
is the wake of latter* destruction and its splinter. ("latter" here is, again, not referring to anything prior with 'latter' and 'former' parts. Perhaps you meant something else?)
How often do the screams reflect upon the foil
as it delivers the oath of hardship through winter?
Oh how it grows weary of response.

Infantry trample and curse along the lowly dirt,
neglecting its thirst, now bloody below the belt.
Marching on, they disregard the destined hurt
as if the king may loathe feeling -love- never felt.
Oh how it grows weary of response and tyrants.

This is my first attempt at reviewing a piece of literature, so it might be a bit.. lacking.

Blue = Good
Red = Not so good/might need changing.

Oh How It Grows Weary

The extension of his arm split the air in two,
filling itself with a lot less than that of pride.
The command to fall strikes the heart of a few;
as widows gaze on the cliff and beyond the tide. Love this.
Oh how it grows weary.

Laying on the ground, hidden within the soil
is the wake of latter destruction and its splinter.
How often do the screams reflect upon the foil
as it delivers the oath of hardship through winter?
Oh how it grows weary of response. As the person above me said, repeating this sentence works great but adding to it makes it less powerfull.

Infantry trample and curse along the lowly dirt
neglecting its thirst now bloody below the belt.
Marching on, they disregard the destined hurt
as if the king may loathe feeling -love- never felt.
Oh how it grows weary of response and tyrants. Same as above.

For the most part I like this, I love the depth and imagery it has, but at the same time it also has a directness about it. But actually, I didn't like how you ended with the same sentence that you just kept adding onto. I actually think it'd be better if you just had "Oh how it grows weary" at the end, and only at the end. But obviously, that's just my opinion. I still like it.
Keep writing,
StoryWeaver