Magic Warfare: Arms, Armor, Spells, and Inventions for War in a Fantasy World

From publisher blurb:

This tome contains the collected information of the greatest tacticians, leaders, and generals from across the planes. Neatly organized into sections detailing subjects ranging from the use of known magic items, new magic items, spell theory, subterfuge, and specialized combatants this information is vital for any would be commander.

Contains:

New, by the rules, uses of existing spells and items.
New spells and magic items.
11 NEW creatures ranging from mobile weapon platforms to ice specialized assassins.
Example military engagements from around the planes.