The international system can influence internal wars in three different ways: by diffusion and encouragement, by isolation and suppression, and by reconciliation. Historically, there have existed four basic types of relationships between external parties and the two parties in conflict: what can be called 'international civil war', in which both parties receive external state support; the case of a 'holy alliance' where there is universal or great power support for the Centre; a 'concert', where third parties attempt to find a peaceful solution; and 'abstention', that is, refusal to become involved at all.1