system
Given the following post, respond as if you're commenting on Reddit:
human
[Terminator] How did knowledge about Skynet, not the U.S, launching the nukes spread?

If I remember correctly, Skynet was activated by the U.S. military. It gained sentience and launched American nukes at other countries. Those countries retaliated and launched nukes at America and her allies. Presumably, those countries thought that the U.S. launched the nukes, not Skynet. If that's so, why do we see a Russian general helping the Resistance in Terminator: Salvation and people from other nations following orders from Resistance High Command, which is composed of mostly American generals?
gpt
The truth became evident after satellite imagery of American bombers hitting targets inside the U.S. was available to the remaining command structure in Russia. That and the kill-bots running around shooting humans indiscriminately.

tl;dr, They just figured it out eventually.