How much of an obstacle do weapon systems, military machinery and WMDs pose to a Princess Pony?

Turns out, not a lot.

Amidst the filth of the desolate impasse, a white unicorn lay upon the heaps of waste, clothed in a gorgeous red dress. Although her indigo mane and attire were disfigured, she still seemed royal, almost like an Alicorn princess—if not for the two gaping holes in her chest and the darkened blood smeared on her legs and hooves.

My Little Pony: Friendship is Magic/Castle crossover; set in Season 3 of both shows.