In the original timeline, when the Mexican–American War broke out, Antonio López de Santa Anna had already been pushed out of the center of power.
After sending troops to reabsorb the Republic of Texas, he had suffered a humiliating defeat.Attempting to recover his standing, he imposed harsh new taxes—only to trigger his own downfall.
But things were different now.
The war had erupted much earlier than in the original history.
Santa Anna had not yet reached the stage where his failures would topple him.
In fact, the timing might even have saved him.
The conflict had begun before he could commit his greatest political blunders.
There was no tool more effective than war for consolidating a leader's authority and rallying a divided nation.
Of course—
Such power only lasted if the war produced results.
If it ended in humiliating defeat, the opposite would happen.
Santa Anna might have been a poor administrator, but he was still one of the most capable military figures in Mexico.
Having already fought the Americans, he knew perfectly well what would happen if the war dragged on.
Mexico would be crushed.
If the conflict could end in a way that preserved Mexico's dignity—
Then the dictator would end it immediately.
That was simply the nature of power.
The Mexican ambassador, Cuevas, believed our demands were excessive.
He was correct.
But his opinion did not matter.
Major decisions were not made by ambassadors.
They were made by the man at the top.
And just as expected—
Around the time the Royal Navy fleet departing Britain began approaching Canada, Cuevas returned with Santa Anna's reply.
He bowed repeatedly as he stood before me.
"President Santa Anna has agreed to accept the British Empire's mediation."
"However, there is one condition."
"The territory must be sold, not surrendered."
"And the British Empire must guarantee that Mexico did not lose this war to the United States."
"That will not be difficult," I replied with a pleasant smile.
"The President has made a very wise decision."
"Unlike the chaotic nations of Europe, there are not many countries on this continent."
"It would be far better if we all learned to coexist peacefully."
"Mexico has always been willing to live peacefully with its neighbors," Cuevas replied stiffly.
"Provided the United States stops provoking us."
"Haha. The United States seems to be reflecting deeply on its mistakes."
"I'm sure we will receive a positive response soon."
"Once that happens, the peace negotiations will proceed as a three-party conference."
"I will inform you the moment Washington sends its reply."
Cuevas still seemed uncertain whether Santa Anna's decision was correct.
But what choice did he have?
Dictator or not, Santa Anna was still Mexico's president.
And when the boss gave orders—
Subordinates obeyed.
Still, one thing was now clear.
Santa Anna's greatest priority was saving face.
Once that became obvious, Mexico effectively lost any negotiating leverage.
If negotiations collapsed, all Britain had to do was conduct a naval demonstration.
And the lifespan of Santa Anna's regime would begin shrinking in real time.
Three days after Cuevas departed, the American ambassador Everett returned.
He looked just as exhausted.
"Congress and the administration have agreed to proceed with negotiations based on the conditions Your Royal Highness proposed."
"Secretary Webster will arrive shortly to lead the talks."
"That was quicker than I expected," I said.
"I assumed it would take a few more days."
The effect of announcing the Royal Navy's deployment had been remarkable.
Operating fleets cost money, of course.
But we had not deployed the entire navy—only a portion for a demonstration.
And with that small investment—
We had secured territory comparable in size to Upper and Lower Canada combined.
Frankly, it was practically free.
"The President also asked me to convey something," Everett added quietly.
"He wishes to assure Your Royal Highness and Her Majesty that he never intended to offend you."
"I see."
"And will the President remain in office?"
Everett hesitated.
"…That seems unlikely."
"As you know, calls for his removal are spreading throughout the country."
"Well, he did cause quite a scandal."
"Will Congress proceed with impeachment?"
"Impeachment has never even been attempted before," Everett replied.
"There was considerable debate."
"But the current consensus is this: if the President resigns voluntarily, Congress will refrain from impeachment."
Everett glanced at me nervously.
He was probably worried that Britain might accuse the United States of protecting Tyler's honor.
But I had no personal hostility toward the man.
If anything—
He had done me a great favor by escalating this crisis.
"Even if he made a grave mistake," I said calmly,
"he is still the President of a nation."
"Forcing him from office in disgrace would be excessive."
"And it would not benefit relations between our two countries."
"I believe Congress has made a wise decision."
Everett sighed in relief.
"Thank you for your understanding."
"Then we shall begin negotiations as soon as Secretary Webster arrives."
"Mexico is already prepared."
"…Understood."
Everett looked uneasy about the treaty we were about to impose on Mexico.
But even without British mediation, the United States would have struggled to defeat Mexico decisively.
Wars required justification.
Men died in battle.
They needed a reason to accept those deaths.
But this war had been revealed as a fabricated conflict.
Northern cities were already seeing protests demanding an immediate end to the war.
The South, meanwhile, was drowning in slave revolts.
Under those circumstances—
No army could fight effectively.
If the war continued too long, soldiers might even turn their guns around.
"Please rest until Secretary Webster arrives," I said.
"I must prepare for the conference."
"…Thank you for your time."
Good.
Both Mexico and the United States understood the situation.
Neither side had the leverage to make demands.
Which meant they would follow my lead.
If they did—
No bloodshed would be necessary.
The Three-Party Conference
"...Good afternoon."
"A pleasure to meet you."
When Cuevas and Webster finally met face to face, their smiles could not conceal the hostility between them.
Mexico had been slapped in the face without warning.
And now it was losing territory.
Of course resentment lingered.
The United States should have felt guilty.
But Americans—being rather similar to the British—rarely apologized sincerely.
If anything, Webster likely resented negotiating on equal footing with Mexico.
"Gentlemen," I said smoothly,
"it is fortunate that we have found a path toward peace before the war grew worse."
"The reason I have brought you together is simple."
"The borders of British Canada, the United States, and Mexico are currently tangled beyond reason."
"If we do not clarify them now, future conflicts will be inevitable."
"I agree," Webster said.
"So do I," Cuevas replied.
"Though I cannot guarantee the United States will keep its promises."
"The United States values trust and contracts," Webster said stiffly.
"We always honor our treaties."
Cuevas snorted softly.
Webster ignored him and turned to me.
"The United States agrees that most of Oregon will become part of British Canada."
"But we have not yet heard your proposed boundary."
"Where exactly do you intend to draw the border?"
"Traditionally, borders follow natural features," I said.
"Mountains. Rivers."
"So we will follow tradition."
I pointed to the map.
"The Rocky Mountains and the Colorado River will serve as the borders between the British Empire, the United States, and Mexico."
Webster blinked.
"You mean… everything west of the Rockies and the Colorado River will belong to Britain?"
"Exactly."
If one looked at the modern map—
Britain would gain Oregon, Washington, and Idaho, while the United States would retain only parts of Montana and Wyoming.
It was absurdly favorable to Britain.
But what alternative did America have?
Fight Britain while dealing with rebellion at home?
Or sign the treaty?
The answer was obvious.
"But what does the Colorado River boundary mean?" Webster asked.
"Everything west of that river belongs to Mexico."
"Ah," I said.
"That is a matter for Ambassador Cuevas."
"As previously discussed, Britain wishes to purchase the territory west of the Colorado River in Alta California."
Cuevas stared at the map.
That region included what we would now call California, Nevada, and Utah.
I had been tempted to push further south.
But greed could cause indigestion.
This was enough.
"Of course," I added,
"the territory will not be taken for free."
"After careful calculation, we believe £2.5 million would be a fair price."
Cuevas nearly choked.
"Two… two and a half million pounds?"
"Yes."
"And if Mexico wishes, we can even use the money to help build railways."
"That land is enormous!"
"Yet President Santa Anna seemed quite satisfied when we discussed it earlier."
In truth, almost no Mexicans lived there.
Between Britain to the north and the United States to the east—
The region would eventually be lost anyway.
Webster suddenly leaned forward.
"Ambassador Cuevas!"
"Surely you are not planning to sell all that land to Britain."
"The United States could pay twice that amount."
"No—three times!"
But Webster's intervention had the opposite effect.
Cuevas' expression hardened.
"The President's decision is final."
"Alta California will be sold to the British Empire."
"For £2.5 million."
"Wait—perhaps we should reconsider—"
"No."
"A promise is a promise."
If Mexico had to surrender territory anyway—
Selling it to Britain was far preferable to losing it to the United States.
Mexico still had Pacific coastline.
But America's access to the Pacific would now be blocked.
Cuevas glanced at Webster's distorted expression.
A faint smile tugged at his lips.
Even if Mexico suffered—
Seeing America suffer more would be satisfying enough.
The rest was simple.
After a few final discussions, the prepared treaty documents were brought forward.
Years of planning had led to this moment.
I picked up my pen.
Webster sighed and did the same.
Cuevas followed.
Black ink spread across the white paper as the three of us signed our names.
And with that—
The short but consequential war in the New World finally came to an end.