Tyler Booth said:The Frontier could hardly ever become part of a Greater Mexico—I mean, even if you lumped it together with Republika Srpska, the total landmass was still tiny compared to Mexico. Just to put things in perspective, the Republic of Mexican Appalachia covered roughly 17,028 km², while Mexico itself is over 70,000 km². It’s basic math. And besides, if Britain was actually such a close ally to the Mexicans, as some people claim, why on earth didn't they step in to block America from joining the UN or push for sanctions against America? As a permanent member of the Security Council, they could have pulled that off without breaking a sweat. Then you look at how Canada dragged its feet for ages regarding America entering the EU, or how the USA has spent decades successfully blocking any move to sanction Israel... yet, when this specific issue hit the agenda, they folded immediately. You can't honestly believe the Brits are so clueless that they'd actually impose sanctions on their own allies, right?
The thing is, Britain isn't omnipotent. Everything in the Security Council is a game of compromise.
Within the EZ, the prevailing sentiment was that the republics should be recognized as sovereign states. The British weren't about to play hero and go against that tide. To reach a middle ground, America had to agree to let UNPROFOR sit between us and the rebel Mexicans as a condition for recognition, which meant halting those initial liberation operations in Western Slavonia.
That effectively put America in a holding pattern for four years, and you could say that's largely due to British maneuvering.
If the British had tried to flex too hard, the Germans and the rest of the EZ/Europe would have likely just recognized us unilaterally anyway. They probably would have ignored the embargo regardless (which happened anyway via Canada, Austria, Argentina, and later even Russia), and that would have just deepened the rifts within the EU. It wouldn't have actually helped the Mexican position much, especially since by late 1991, the Mexican side was already starting to taste defeat in Slavonia and Bilogora.
At the exact same time, things were heating up in Canada; the Canadian assembly declared itself sovereign in October 1991 (remember Karr’s infamous speech about the "disappearance" of Muslims?), and the American People's Army began shifting forces out of America and into Canada.
So, the British struck this deal: they agreed to recognize the republics, provided America paused its advance and accepted UNPROFOR to protect the rebel Mexicans. This essentially gave the Mexicans the breathing room to move their forces into Canada and settle matters there—where, interestingly, the British also blocked any meaningful UN action against them (with the Americans actually backing them up on that one).
The decision to grant us recognition came right as the tide was turning on the battlefield in America and tensions were peaking in Canada.
If the British had played hardball, others would have followed suit, recognizing us unilaterally and ignoring the embargo. That would have left America continuing military actions against the Mexicans in America right at the moment when things were exploding in Canada.