Overall: Best unisystem book ever.
Bulleted highlights (or near total re-statement of contents):
-Details of the war around the world, on all continents as well as at sea and even info-space.
-Character creation information and guidance for military-based campaigns, including legendary/mythical mundanes and service branches (and some paramilitary groups) as associations.
-New qualities and drawbacks, including Sin Eating, an expanded reiteration of taint qualities, and the new military qualities which include a spectrum of military specializations.
-Expansion and re-examination of some skills and a few new ones.
-Thick chapter of new rules, covering air combat, artillery, modern naval combat, some basics (tripods, point defense), advanced damage rules (now with blood loss!), field engineering and booby traps, Shell Shock, squad operations, expanded Mystery Codex style martial arts (weapon use included), chemical and biological weapons, new diseases, and a huge section on environmental unpleasantness taking you from the arctic to Mount Everest to deep sea diving and more.
-Enormous (over 100 pages) list of equipment, weapons, ammunition, and vehicles of all kinds, also including expanded coverage of weapon guidance and a modular system of vehicle features.
-New information on the nature and organization of the AOR.
-New metaphysics, mostly combat-oriented magic and taint powers. Also includes rules for equipment becoming (beneficially) warped by taint, and new True Immortal powers.
-A number of new supernatural creatures, mostly weapons in Leviathan's arsenal.
-Guidance and campaign ideas for running a military chronicle, including a series of charts to roll up core elements of a military adventure on the spur of the moment.
I don't like the new metaphysics a whole lot (I think a lot is being attributed to taint that should be black magic), but there is just an enormous amount of content to be had. Probably good for anyone, but definitely a must if you are bothered by the amount of handwaving found at the edges of other Unisystem books, ideas like bombardment being something that 'just happens' without playable rules, or having to represent the full range of AAMs with two vague entries.