Core takeaway
The case for moving to a world of spheres of security
We are instead destined to live in a realist world, where spheres of influence are part of the warp and woof of daily life.
Key questions
How should the security needs of great powers be balanced with the sovereignty of smaller nations on their border?
The concept of Spheres of Security limits the activity of other borders of other great powers.
Mexico has the freedom to engage in political and economic cooperation with any state, yet Mexico does not have the freedom to host Russian missiles or Chinese military bases.
This is common sense and must be applied to all great powers, yet how feasible is such an agreement between the great powers?
1. On 15 October 2025, I was on Glenn Diesen’s podcast with Jeff Sachs talking about Jeff’s newly minted concept of “spheres of security,” which he sees as a major advancement over “spheres of influence.”
He opened the discussion by making the case for moving to a world of spheres of security and I then explained why I think that is not possible and we are instead destined to live in a realist world, where spheres of influence are part of the warp and woof of daily life.
John J. Mearsheimer is the R. Wendell Harrison Distinguished Service Professor of Political Science at the University of Chicago, where he has taught since 1982. Jeffrey D. Sachs is a world-renowned economics professor, bestselling author, innovative educator, and global leader in sustainable development.
