> Becker argues that a basic duality in human life exists between the physical world of objects and biology, and a symbolic world of human meaning. Thus, since humanity has a dualistic nature consisting of a physical self and a symbolic self, we are able to transcend the dilemma of mortality by focusing our attention mainly on our symbolic selves, i.e. our culturally based self esteem, which Becker calls "heroism": a "defiant creation of meaning" expressing "the myth of the significance of human life" as compared to other animals. This counters the personal insignificance and finitude that death represents in the human mind.
> Such symbolic self-focus takes the form of an individual's "causa sui project", (sometimes called an "immortality project", or a "heroism project"). A person's "causa sui project" acts as their immortality vessel, whereby they subscribe to a particular set of culturally-created meanings and through them gain personal significance beyond that afforded to other mortal animals. This enables the individual to imagine at least some vestige of those meanings continuing beyond their own life-span; thus avoiding the complete "self-negation" we perceive when other biological creatures die in nature.
You can find big similarities such as the promised land as the immortality vessel, heroism as a response to historical trauma and the ongoing attacks on their sovereignty, and the immortality project would be the nation-state. Becker goes on to categorize all of this similar to a mental illness. You can read the wikipedia page here, I find it very helpful: https://en.wikipedia.org/wiki/The_Denial_of_Death
TL;DR: If you look through Becker's lens, you start to realize how stupid such wars and expansionist ideals seem. People should focus on what exists now and stop chasing projects that'd span beyond their lifetimes while making life today worse.
The book doesn't support anything in "their" favor. The idea boils down to nobody being "them".
Related part from Wikipedia:
> Becker argues that the conflict between contradictory immortality projects (particularly in religion) is a major source of the violence and misery in the world such as wars, genocide, racism, nationalism and so forth since immortality projects that contradict one another threaten one's core beliefs and sense of security
