Almost every internal war has an external component. Some external effects are purposive, where external actors aid and abet internal factions and governments.
Some external effects are unintended.
Another example would be the actions of humanitarian agencies, which, while aimed at relieving suffering of vulnerable populations, provide warring groups with needed food and supplies to continue a war. Another example would be well-intentioned mediators, who fail to see likely problems in the agreements they create. There are cases, however, of purposive international action that prevented, mitigated, resolved, or managed internal conflicts. Analysts point to the successful preventative deployment of peacekeepers into Macedonia, and the protracted diplomatic attention given to that country, as key factors in preventing the spread of war to that country. Several tense transitions of authoritarian states in Africa resulted in peaceful, democratic transition, rather than protracted, bloody civil strife.