In Europa Universalis II, AI milking is a means of exploiting the AI's special rules for profit. The AI war economy can be exploited by the player, so long as the enemy country has little to spend money on. Unlike a player the AI will be able to build units in a war incessantly, so long as they control any uncovered province where they have Build Capacity. This makes it imperative for the human player to cover an enemy's country entirely, as soon as possible.