You go on a planet that is not your own, 
planet XYZ.  

You breathe the air, 
drink the water, 
eat the food.  

Your molecular composition is not from planet XYZ.  
You decide to leave and return to your home planet, 
leaving planet XYZ in your destruction.  

But when you return to your home planet, 
the elements from planet XYZ is all in your system.  
They begin to react 
with the elements in your home planet.  

The water from XYZ runs through your body 
into your brains and causes damage.  
The air you breathe at your home planet 
acts as a catalyst to the elements in your body, 
causing destructive damage to your mind 
and your body.  

You are no longer safe in your own world.  

For the elements of XYZ that you consumed 
are still alive in your body, 
they bring forth life 
like any element on any planet.  

These life forms, XYZ elements, 
know what you did on its planet 
and have taken action 
against the action 
you took against its earth.

Do you really want to wage war 
against mother earth, 
on any planet?