Sole Supplier — Some extremely important resource is exported from this world and this world alone. It’s unlikely that the substance is critical for building spike drives unless this world is also the first to begin interstellar flight, but it may be critical to other high-tech processes or devices. The locals make a large amount of money off this trade and control of it is of critical importance to the planet’s rulers, and potentially to outside powers.
Rigid Culture — The local culture is extremely rigid. Certain forms of behavior and belief are absolutely mandated, and any deviation from these principles is punished, or else society may be strongly stratified by birth with limited prospects for change. Anything which threatens the existing social order is feared and shunned.