Well, there was one, I didn't actually read, but . . .
Sit around the fire and listen to the Old Prospector bloviate.
Back in the Elder Days, when soc.history.what-if and alt.history.what-if were the places for online AH, we didn't have none of them boards or sich, there was a feller . . . oh, never mind. There was a poster on the SHWI and AHWI Usenet who was called "Quonster". He had several appalling opinions, saying things like, for example, that Hogwarts would have thrown Harry Potter out when he showed up for the first day of class, if he had been in charge. And others. One of his usernames was Backto1913.
Anyhow, he claimed to be a "Peninsulare". Which was his term for being a Korean. And one day he began to write about a Korean future-war book. This epos was titled Def-Con. It was written by a popular Korean writer named Kim Kyungjin, with the aid of a team of Korean generals and admirals as technical advisors.
[There seems to be a real writer named Kim Kyungjin, and I once saw a page for a book titled Def-Con by Kim Kyungjin on Amazon, but they wanted too much and had no description.]
The scenario was that the two Koreas had reunited. The United States had gone to war with the united country.
The Koreans sent the personnel of an infantry division, and several ex-North Korean commando teams, to Mexico, which had fallen into even worse drug-gang anarchy. This unit moved to the north and invaded Texas.
The Koreans took weapons from Texas National Guard armories. The Texas National Guard seemed to be helpless. The governors of the neighboring states refused to send their National Guard units to Texas.
The commandos spread out over the south and west. Bridges were destroyed, making it impossible to move up troops. Single commando teams destroyed entire defense plants.
The Mexican-American population revolted and joined the invaders, highlighted by the Mayor of San Antonio, a Chicano, declaring for the Koreans.
Once Texas was secured, the Koreans turned west and attacked California.
Now to be fair, the entire rest of the posters tore this apart, and Quonster continued to post justifications. But it still sticks in my mind as one of the worst AH/Future-war books I've ever heard about.
As I recall, Quonster disappeared a little while later, saying he would be back in three months. He never came back, it seems.