There is both fear and defiance in this horse's eye, but why?

The horse was NOT scared
I’m a war horse and nobody messes me with me
Not even aliens who think they’re big and hard!
Or so the horse defiantly thought
Well he also thought he was a horse but but but…

The horse was actually a spaceship!
Low and behold in all his glory
A real spaceship that was in space
To venture between the stars
And he was horse shaped.

But was made of aerospace grade materials
That was mined from distant asteroids
And built into a starship in a factory
That orbited Neptune for ease of use
For cosmic exploration and so more.

The horse shaped space vessel was big
Many miles high and across and heavy
Like the heaviest metal played by Compressorhead
Or mined from the most lucrative asteroid
Powered by fusion drive and ion engines.

Armed with triple laser cannon arrays
For defence against meteors and alien craft
Like now that were ready for war!
Zap! Zap! Zap! went the lasers guns.
Boom boom boom went the alien craft.

And Yahoo! whinnied the horse craft
As he became master of the galaxy
And unleashed war of the worlds
Thus dooming the entire universe
To violence and darkness if aliens won.

But a million horse shaped spaceships
Were being built in deep space
Up-gunned with undreamt of weapons
And uprated engines and other toys
Thus guaranteeing galactic horse victory.

There was no need for a human crew
Machines and robots took over
Ensuring a flawless capacity for success
As a hundred thousand ships sped off
To impose equine discipline in space.