The Moral Animal by Robert Wright
Overview of human psychology and sociology from an evolutionary viewpoint. It's probably dated by now, but I haven't seen a better high-level book for the layman. Key points to keep in mind is that humans are hierarchical animals, always wanting to increase or protect their status, and forming coalitions to do so. Lying and treachery are key tools in this.
Someone with a good grasp of human nature probably wouldn't learn much from this, but for a near-autistic such as me it was illuminating.
Non-Zero by Robert Wright
Overview of human history looking at the increasing complexity of social arrangements. It's a culturally deterministic view, if you include metal-working and other technologies as part of culture. Or you can consider it technologically deterministic if social arrangements such as tribal chiefs, religious ceremonies, and trade contracts are technologies. History is driven by the conflict between the current leadership of society wanting to suppress new innovations to protect their status, and competing societies trying to out-innovate each other to survive. Wright looks forward to society reaching an "end game" stage where all governments would merge in a single global order. He thinks we're close to pulling that off. I think we've got a long way to go.
This is a good rebuttal to Guns, Germs, and Steel. GGS is helpless with questions such as "Why did China fall behind Europe?" while NonZero tackles them directly.
The Future and Its Enemies by Virginia Postrel
The lessons of Non-Zero in current practice. Postrel divides our political factions into reactionaries who want to resist or undo changes to preserve their desired social order, technocrats who want all change controlled by a single group of professional decision makers (both called "stasists"), and dynamists who encourage change to bring progress in all parts of life. Neither political party is strongly identified with dynamists so they tend to be among the politically homeless (though "trash the current order in the MidEast and hope that improves things" is clearly a dynamist approach).
Predates 9/11 but holds up well. After the 2000 election I read an article pointing out a 36-year cycle in what issues dominate American politics and how we were due for a new one in 2004. I wondered if stasists vs. dynamists might become the new dividing line in politics. Instead Al Qaeda gave us something else to argue about.
The Transparent Society by David Brin
A thoroughly convincing case that privacy is a dwindling relic of the 20th century. Spying technology is getting better faster every year and there's no stopping it. Preserving freedom won't come from trying to preserve the illusion of privacy but by making sure the Powers That Be are also exposed to our scrutiny.
The Clash of Civilizations and the Remaking of World Order by Samuel Huntington
This is the Big Book on the current war and potential ones. It looks at what's driving the post-Cold War wars worldwide and how the balance of power may shake out long-term. More focused on motives than capabilities. A key premise is that the conflicts between civilizations are more significant than the internal ones. I sometimes wonder if the West's internal stresses will stay at that low level.
The book I haven't read that seems most likely to get added to this list:
The Anglosphere Challenge: Why the English-Speaking Nations Will Lead the Way in the Twenty-First Century by James C. Bennett
Edit: I did get to read it later, and it is on the list.
The book I haven't read that I'm most afraid will trash my optimistic scenarios:
World on Fire: How Exporting Free Market Democracy Breeds Ethnic Hatred and Global Instability by Amy Chua
New books on the list:
The Rational Optimist
A comprehensive look at how trade and cooperation have lead to continuous improvement in the human condition from the stone age to now. This is effectively bumping Non-Zero off the list as it's doing a better job of covering the same issues.
The Righteous Mind
Fascinating look at human psychology, particularly how we're prone to immerse our identity in tribal groups. Has huge implications to how our politics work in practice. Does a good job of explaining why so much of our political discourse is "my tribe good - your tribe bad" instead of discussing issues.
Illustrates how it's actually easier to replace institutions than for them to adapt for a new situation.
I still haven't read Chua's book yet.