The Three-Body Problem focuses on three complementing issues: environmental destruction, cultural decadence, and reliance on technological advancement. The book opens during the Cultural Revolution in China, where Red Guards punish scientists for not following sufficiently Maoist beliefs. The mere reporting of scientific results is deemed treasonous because they do not comport with Maoist beliefs. This occurs despite China's desire to advance its own scientific achievements.

Later, we see Ye at a work camp where the forest is being decimated for no apparent reason other than to make members of the work camp perform manual labor. It is largely seen as an environmental catastrophe, but it continues to be used by the government. Even later, we find that Mike Evans is working to replant the trees that have been clear-cut, though it is an ultimately fruitless endeavor since the trees are clear-cut again after Mike Evans leaves. Here, the environment is decimated as an exertion of the government’s power. Overstep the government and you will be punished. Overstep the limits of Earth’s bounty—as Ye believes humanity has done—and the Trisolarans will punish humanity.

Technological advancement is deemed important, as it is the means through which extraterrestrial life is ultimately discovered and the only means for defending Earth. Most of the technology is not used for environmental support, and it further degrades the environment. When Ye essentially opens the mode of communication between Earth and the Trisolarans, she changes the fate of Earth and human life forever. That being said, her personal legacy will be lost in the remnants of the world as she knows it. There is a suggestion being made here that our interpersonal connections are our legacies. Technology or newfound advancement will not remember us; the people whose lives we touch will hold our echoes. Perhaps Cixin is calling for a return to human connection to remind us of what endures: our shared humanity.

The destruction of the environment is one reason for the development of the ETO, which works to undermine humanity's achievements in order to ease the invasion of the Trisolarans. Additionally, the cultural oppression and decadence of China during the Cultural Revolution ultimately provided the motivation for Ye to betray humanity and provide the Trisolarans with the location of Earth. Both Ye and the ETO work towards supporting the future invasion because they believe it is necessary to prevent the self-destruction of humanity and the continued destruction of the planet. We learn that these aims are misguided because the Trisolarans have no desire to coexist with humanity. However, Ye and the ETO have little to no faith in the abilities of humanity to save itself.

The book’s title, The Three-Body Problem, is worth analyzing, too. There is great significance to the number three. Trisolaris has, predictably, three suns. Each of the suns has a substantial effect on the planet. In addition, there are three factions that the ETO splits into: the Adventists, the Redemptionists, and the Survivors. By emphasizing threes, as well as the prominence of the pendulum, the text focuses on the dynamism of experience. Polarity in terms of linearity loses significance because a spectrum is favored. 

Ultimately, the book focuses on the lengths that some may go to do what they believe is necessary to prevent the extinction of their race. It also sounds a negative note on the outlook of humanity, though some hope does remain.