Agression
Many of the characters in Leviathan Wakes are incredibly aggressive. In order to keep the peace on Eros and in the solar system more generally, Joe Miller has to take aggressive actions. He beats people up and interrogates him to accomplish what he needs to accomplish. Other humans must do similar things to survive in thrive in a relatively bleak world. The Martians also act in similar ways: to prove their point, the Martians act aggressively. For instance, one of the Martian warships shoots the Canterbury out of the sky, killing quite a few people. In the world of Leviathan Wakes, people had to be violet and aggressive in order to survive. If they weren't aggressive, then they wouldn't be successful, and no doubt wouldn't have survived. After all, the world of Leviathan Wakes is a harsh and unrelenting one.
Colonialism
After humanity invented the capability to travel between planets, the solar system was opened up. As has happened over the course of history, humans used this new opportunity to engage in colonialism and exert their power over peoples who can't really effectively fight back. Like the Martians, Earth and humanity once again became colonialists. They took control of a number of planets, including Venus, and took control of the asteroid belt and other smaller planets. Ultimately, Leviathan Wakes is a novel which shows the dangers and pitfalls of colonialism and how being colonialists can negatively impact the colonialists and those who are colonized in different ways.
Power
Power is an important theme in Leviathan Wakes. In the solar system, there are two factions vying for power: the Earth, which is governed by the United Nations and Mars, which is ruled by the Martian Congressional Republic. Each organization is obsessed with conquering and keeping a stranglehold on everyone in the solar system and achieving economic domination. But weak people can't conquer anything and keep their grip on anything; powerful people can, showing how important having power is.
