Although advances in transportation and communication have made the world more interdependent in some senses after World War II, nuclear weapons, nationalism, and the proliferation of small weapons have made cross-border wars much less frequent. And if they are a threat to US security at all ? which most aren't ? cross-border wars are more dangerous than now much more frequent internal civil conflicts.
Yet the United States has unnecessarily overthrown in regimes in Afghanistan, Iraq, and Libya that have led to internal civil wars and the spread armed Islamism into surrounding areas. Unbelievably, despite these debacles, some members of the foreign policy elite ? for example, neo-conservative American triumphalists ? want the US to get more heavily involved in other civil wars, such as the ones in Ukraine and Syria. No matter that these internal wars do not affect US vital interests and that the United States, with a more than $17 trillion national debt dragging a sluggish economy, can no longer afford to be the world's policeman. If the United States continues to try to do so, it could eventually lose its great power status ? as did the financially exhausted British and French Empires after being on the winning side in the two world wars.