[mech998877]

History has shown that having a multitude of roughly-equal competing powers results in more per-capita death from war than when there is 1 or two dominant nations. The 1800's and early 1900's were bloody. Post WWII has had less death from war.

[JumpCrisscross]

Bilateral is stable. Multilateral is not. We have limited evidence nukes change that. Currently, with the implosion of Pax Americana, we’re hearing words a multi-lateral theatre in the Middle East and Asia. Hence the heightened risk of nuclear power in one of those settings. (Europe remains a bilateral theatre.)

[chistev]

Maybe because of nukes now.

[flossly]

Or mass media.

[xg15]

True, though post-WWII was not a single power either until the 90s. We've had several decades of Cold War in which there were at least two great powers.