Or lady Trieu is a true believer in Ozymandias and her plan is to free him and launch a 2019 version of what he did in the 80s. Killing half the people in the world to slow climate change would be logical but we haven't seen any indication that climate is an issue in this universe.
All the cars are electric cars, so this world already seems to care more about climate change than our own world.
Given the Vietnam flashback of her daughter, which implies Trieu has had a traumatic experience in the war (courtesy of the US) and Will's traumatic experience as a boy in the Tulsa massacre, I wouldn't be surprised if the two are banding together to bring down (white) America.
In the movie we saw Dr. Manhattan killing half of Vietnam all by himself. Maybe the Millennium Clock is all about launching an inter-dimensional attack on Dr. Manhattan in order to get revenge for Vietnam? She needs a Dr. Manhattan killing weapon, along with the ability to generate some kind of "tachyon" field to block his ability to see the future.
If that's her plan, she might be working with the Russians on the Intrinsic Field Generator that the reporter was asking the Senator about.