Good question.CatharzGodfoot wrote:History-wise, why is it that Mexico invades NAN, gets expelled, NAN collapses, and Mexico doesn't re-invade and 'restore order'?
The NAN wasn't one country, it was a political and military alliance of 4 separate countries. Each is economically and militarily weak (for demographic reasons), and have long harbored resentments towards each other.
The United States is defederalized, and is also economically and militarily weak. There are no standing Federal armed forces. In times of war, each state is expected to raise army units and put them under Federal command. (In theory. This has never actually happened.)
Some states, including Texas and California, maintain standing army units. These are known as "National Guard" units, and are the only standing armed forces in the US. (Though a few Federal military agencies still operate, like the OSA, USAMRIID, the NSA, and so forth.)
After VITAS, Mexico became a military dictatorship, which gradually phased into a federal republic. It didn't maintain a large army, basically a force sufficient for defense but not conquest.
There was a band of Awakened rebels, allied with or lead by a Quetzal, which claimed and ruled the Yucatan peninsula. These rebels launched a coup, and conquered Mexico. They renamed it Aztlan.
Part of their goal was to reclaim Aztlan's historic greatness. This included efforts to retake territory lost to the US in the US-Mexican War (1846-48). Within a year of seizing control, the new nation attacked the southwest, including the southernmost NAN nation (the Pueblo-Navajo Coalition, basically New Mexico and Arizona), California, and Texas.
It faced the combined forces of California and Texas National Guard, the Ute Army (largely made up of those pinkskins who remained in the Ute Nation), and the forces of the PNC. The Great Sioux Nation refrained from sending any forces, because of long-standing enmity with the Utes, and the Pacific Tribal Council lacked any notable military units.
Aztlan steamrolled the PNC, but was stopped by Ute and California/Texas forces. Aztlan wasn't, at that time, the military powerhouse it would soon become. Essentially, the junta attacked before it was ready.
The PNC was absorbed into Aztlan as the state of Chicomoztoc. It bordered on the three belligerents in the war, California, Texas, and the Ute Nation.
The NAN alliance broke up after the war, because of internal political arguments. The Ute Nation (renamed the Ute Council) resented the other two Nations for not providing any support during the war. The Great Sioux Nation, highly insular and economically depressed, was satisfied with letting the Utes go their own way. The Pacific Tribal Council would rather the alliance remained intact, but could not convince the other two to reconcile.
After the war, Aztlan faced the same forces that previously defeated it: the armies of California, Texas, and the Utes. It began a program of aggressive military expansion, and concentrated on absorbing the countries of Central America. (Which it did with relative ease.)
By the beginning of the campaign (in 2032), Aztlan has been reinforcing the border with North America for a year or two, and clearly has the upper hand, militarily. None of the American Currency Blocs have yet raised forces, or provided money for the Federal government to do so, and California and Texas are both strained supporting the units they currently have, as is the Ute Council.
OSA predictions are for war within the next year, a war the United States (and the former NAN nations) will lose. They are desperately trying to find the means to defeat Aztlan, before large parts of NA become part of the country, and the rest impoverished satellite states.
So, the reason Aztlan didn't invade the Ute Council was that it was facing the same armies that had defeated it. It didn't yet have sufficient military power to successfully invade the territory it claimed as its own. That situation has changed.