The ability to attack an area but not hold it encourages cultures in which raiding is the preferred form of warfare. You're never out to conquer your enemies, only to take their resources. You see this situation in archipelagos and in places with small patches of arable land but good transportation, like Scandinavia. Although the Vikings did eventually colonize several areas of Europe at large, it was more for the purpose of having a staging ground than to take more land. Swidden agriculture (jungles) also encourages raiding, since there's not really any value in holding onto land for more than a couple of seasons. Plus, it's difficult to organize large populations when nobody stands still for very long, and smaller tribes tend more toward raids than war.

Hmm… The amount of energy provided by the environment and the amount necessary to survive can have a strong influence on the behavior of the people. The Inuit don't have much inclination to do much other than hunt, make tools, and tell each other stories. You seldom find them fighting because they need absolutely all of their calories just to keep their bodies going in the cold. Even their hunting methods are designed to expend as little energy as possible. A society capable of producing a large surplus of energy, on the other hand, can afford to squander it in the pursuit of luxury, amusement and war.