The Prompt(s): East of the Sun and / or West of the Moon
(The East/West connotation is left/right political leanings, I admit sort of a weak connection. As mentioned in the prompt forum, this fic doesn't represent any current or past real-world political thing, it's just a fanfic.
Princess Twilight Sparkle sighed, looking down at the map of Equestria, flat against the table in the Royal Study, deep inside Canterlot Castle. The situation was fairly obvious, though perhaps the solution wasn't. "Okay, so... Once more. We have reports of a changeling army coming out of the badlands to the south."
"Yes, Twilight Sparkle." Princess Luna's voice showed her growing frustration with the prolonged talks. "As I've said, we could drive them away with a minor show of military power. The passes through the mesas there are narrow. It would not take many soldiers to hold them."
Princess Twilight glanced toward Princess Celestia, knowing an argument was coming.
Princess Celestia smiled tightly. It wasn't her normal, placid, regal smile. This smile was wrung through with disapproval. "Dear sister, that would cause needless loss of life. If we only drove them slightly eastward and northward, we could rely on the forests and the Foal Mountains to slow their advance until they turn back."
"But-" Princess Twilight felt surprised that she was able to get that word in.
"And sacrifice Dodge City? Our old castle? How many changelings would stay in the Everfree Forest, Sister? We must show these invaders that we will not be swayed!"
"Prin-"
Princess Celestia sounded as though she were instructing a disobedient foal. "Luna, things do not work as they did a thousand years ago. We can not simply throw the Guard at every problem. Besides, they would easily be outnumbered. You have been gone a very long time, and-"
Anger flared in Princess Luna's tone. "Whose fault is that, dear sister?"
Princess Twilight's horn flashed brightly, leaving both other alicorns in the room blinking and covering their eyes with their hooves. Twilight felt a pang of something like panic at having done that to the other Princesses, mixed with a sort of pride that she even could. She spoke in a quiet tone. "Princess Luna, Princess Celestia, please, don't argue about that. We need to make a decision, we don't have forever to talk about this."
Celestia recovered first, her voice contrite and much more even. "You are right, dear Twilight. We are all friends, and we should act like it."
"I am sorry, Sister." Princess Luna offered her elder sister a smile, forced as it was, and the resentment seemed to be washed away as Celestia returned it.
"Friends! That's just it!" Twilight clapped her hooves together, and her horn glowed with a long-range teleport spell.
A brief explanation of the problem later, and after some poring over the map with the assorted ponies, Twilight felt that she could ask again. "So, that's what's happening. Princess Luna feels like we should stop them with the military, while Princess Celestia was hoping for a slightly more passive approach. What do you girls think?"
Four voices started speaking at once, and Twilight had to raise her voice to put a stop to it. "Ah! One at a time! Uhh, Spike, you can pick who speaks first."
"Um..." Spike took a moment, standing at Twilight's side, and then pointed to Rainbow Dash.
Rainbow Dash grinned and pulled Spike to her with a foreleg, rubbing his spines with a hoof. "Yeah, that's right! Anyway, Princess Luna's right! Let's go in there and kick their flanks! Don't just push them back, let's make sure there aren't any left to invade next time!"
Princess Luna's brow knit slightly. "Rainbow Dash, I do not think--"
"Hey! You don't have Spike, you can't talk!" Rainbow grinned, holding up the baby dragon as if he was a teddy or something. Princess Luna just rolled her eyes and sighed.
"Hey, what-" Spike managed a few words as Applejack quickly grabbed him away from Rainbow, and spoke her own piece.
"Now you listen here. I ain't saying we need to go killin' each and every one of them bugs or anythin', but I can't have 'em marchin' all through my orchard and fields. They'll trample everythin' alive in there, an' that's saying nothin' about how much Ponyville would get messed up havin' all them liars running around pretendin' to be real ponies. I say beat 'em back hard enough to make sure they don't try it again."
Spike suddenly glowed with a purple-ish magic, one he was pretty familiar with. Twilight lifted him from Applejack's forelegs and set him down beside her, on the opposite side from the farm pony and her loud pegasus friend. Twilight smiled, though there wasn't much mirth in it. "Rainbow, Applejack, those are just... worse than Princess Luna's idea! We can't just kill them all, they may look like bugs, but they're still thinking creatures!"
"Um, I agree." Fluttershy spoke, and then halted, as if realizing she was out of turn. Spike sighed, and took a few steps over to stand under her wing. Fluttershy smiled at the little dragon, and spoke again. "We could, um... just let them talk to us, or visit. Maybe they're just hungry, there isn't any love in the badlands, and... we... um...."
Her voice trailed off at the looks from her friends and the Princesses, ranging from disbelief to appalled. The awkward quiet only lasted a moment before a pink blur swept Spike up and onto her head, the dragon only able to make a panicked noise before realizing whose frizzy pink mane he was all tangled in. Pinkie smiled, forelegs wrapped in a hug around a somewhat startled Fluttershy. "Yeah! We could invite them to Ponyville, and have a super huge costume party! Everypony could have a double and a triple and a double-double and it would super fun and exciting! Nopony would know who anypony really was, and it'd be so full of happiness and love that the changelings wouldn't even HAVE to invade!"
Princess Twilight's face wore an expression that Pinkie had become fairly familiar with, as she pulled her number one assistant out of Pinkie's mane and set him beside her again. Twilight Sparkle sighed heavily, glancing to Princess Celestia before speaking to her remaining friend. "... Rarity?"
Rarity smiled and pulled Spike to her, the baby dragon seeming much happier with this situation than any of the other ponies taking him. She gently ruffled his spines and held him close. "Oh, just look at what all this discussion has done to my little Spikey-Wikey! As for you, Twilight, Darling, I am not a strategist, and I simply don't understand why I have been interrupted for this. I have an incredible amount of work to do for the fall line, and fall will be coming regardless of any nasty little changeling business."
Twilight's horn glowed, before sending Rarity and Spike back to Ponyville again. She let her head fall forward against the table, as Rainbow Dash leaped across it to fuss at Pinkie's ideas, and Applejack started in on Fluttershy's varmint-lovin' nature.
Sometimes, politics were just impossible.