Where it stops depends upon the country and the threat it poses. North Korea presents a special set of risks because its artillery can destroy much of Seoul and because President Carter's deal allowed them to develop nuclear weapons. The horrific nature of such a war changes the decision making process. On the other hand, the French leadership may not like us very much because we have cut off its deals to sell weapons to Saddam and its share of the oil for food profits. But, it can hardly harm us, so the risk that invading it poses to the vineyards offsets the benefits from an invasion. Iraq presented a threat, and we could do something about it.
Distinguishing among such situations is what you must do in the real world where barbarians are willing to saw off the head of Nick Berg or use airplanes as cruise missiles to kill thousands.
Distinguishing among such situations is what you must do in the real world where barbarians are willing to saw off the head of Nick Berg or use airplanes as cruise missiles to kill thousands.