The Hot War is an alternate history series by Harry Turtledove. According to the Del Rey and Bantam Sampler, 2015, it is a trilogy. The first volume, Bombs Away, was released in July 2015. The second volume, Fallout, was released in July 2016. The concluding volume, tentatively titled Armistice, is to be released in July 2017.
The point of divergence is November 1950, when Chinese troops intervene in the Korean War, and do a much more thorough job of destroying various American forces between the Chosin Reservoir and Hungnam. (In OTL, the U.S. forces were defeated, but were able to successfully evacuate from Hungnam and inflict heavy casualties on the Chinese.) This prompts President Harry Truman to allow General Douglas MacArthur to use atomic weapons in Manchuria in January 1951, which prompts the Soviet to attack in Europe in retaliation. They drop atom bombs of their own in England, France, and West Germany, forcing the United States to join a hot war to defend its NATO allies.
As is typical with Turtledove's multi-volume works, The Hot War embraces a number of POV characters, and rotates through them to tell the overall story.