The Post-War Period
The United States entered the post-war period with great hopes. The great menace of the western hemisphere had been defeated, and the American military and economy were the strongest in the world. The main immediate goal for the US was to repair and establish firm control over the new territories gained during the war. In just a few short years, the US had repaired the damages done to the former Turkish territories, and the entire nation enjoyed a period of unprecedented prosperity.
Global Events
After and even during the war, however, global politics were in chaos. There were almost no alliances whatsoever. The US had hoped that Songhai and Russia would set aside their differences in order to stand united against any future Turkish aggression. These hopes fell apart, however, when Russia began to denounce Songhai a few years after the war.
There were also troubled relations in the east. The Aztecs remained officially at war with Persia, although they could not attack Persia without coming through American territory. Japan and the Aztecs also remained bitter enemies, and fought another war in which the Aztecs captured some Japanese territory. But even after the war, things remained pretty much the same.
Isolation
For years now, the United States had refused to entangle itself in alliances with major foreign nations. Although the US had sided with Songhai and Russia against the Ottomans, it refused any lasting alliances with the two nations. They were still dictatorships, and the US wanted nothing to do with it.
And now, with the war over, the United States retreated into neutrality. Avoiding most global politics, the US resolved simply to defend it's vast domain of freedom, with the hope of seeing democracy spread across the globe.