But if we don't do anything, where's the strategy ?
Making strategic choices is not the same as making tactical choices.
In many games, you make both strategic as well as tactical choices.
For example, in a game like Warcraft, you define both the strategy (what types of units you will play, where the groups of units go) as well as tactical (what individual units do during a battle, flanking maneuvers, etc.)
In games like this, you take the role solely of a strategist. You guide the overarching strategy of the game, but an actor (in this case a computer program) takes over the tactical play; it makes the moment-to-moment decisions.