The United States, still the dominant military power in the world, is immersed in a new era of warfare that it has not yet recognised as endemic and enduring. America is losing its wars to less powerful but more adaptable adversaries, while preparing inadequately for future inter-state conflicts. Read by Leighton Pugh.

Image: Posters of slain Iranian Revolutionary Guard General Qassem Soleimani. Credit: Associated Press / Alamy Stock Photo