Each country in Call of War belongs to one of four Doctrines: Axis, Allies, Comintern and Pan-asian.
Doctrines grant various advantages or disadvantages, emphasizing different styles of play. Successful Generals know about these differences and use them to their advantage. It is recommended to select countries with different Doctrines when starting new game rounds to learn them in practice. Which Doctrine belongs to which country is shown in the country selection screen and in various other places in the game.
Each Doctrine has a main focus with general strengths and weaknesses, which are applied to all units of a Doctrine. Furthermore certain units of each Doctrine gain additional advantages or disadvantages, which are added on top of the general strengths and weaknesses (note: The percentage values are added up before they are applied to a unit). Doctrines also alter the day of availability of units, with unit levels becoming available earlier or later. These availability changes do not affect research levels on day 1 though.
Below is a Doctrine overview table listing all general strengths and weaknesses as well as all additional advantages (green) or disadvantages (red) of units.