Conflict trap

Conflict trap is a term to describe the pattern when civil wars repeat themselves.
Description.
Scholars have offered a few reasons for it, after Paul Collier and Nicholas Sambanis (2002) noticed this pattern and coined the term ‘conflict trap’. Firstly, a civil war can aggravate the causal political and economic conditions which lead to a repeat civil war. Other reasons can be because the combatants are fighting over stakes that is valuable to both the parties, combatants are unable to defeat each other or are engaged in a long duration serious war.
Political and legal Institutions play an important role in inhibiting a repeat civil war, hence preventing a country from entering a conflict trap. Strong institutions can put a check on the incumbent's power, hence ensuring public welfare and therefore rebels have fewer reasons to restart a civil war. Also, this removes the need for the rebels to maintain an army or a threat of war. A strong political and legal system also gives a non-violent platform to rebels to bring about desired changes, so they may not need to adopt violent ways to protest.
There can be other reasons why a civil war may start and repeat itself. There may be intense grievances held by the groups, which motivate them to fight. Inferior health conditions, lower GDP and poor human development create conditions for dissatisfaction, and hence civil wars. If a country is poor, it may be easier for rebels to organize an army and start a civil war. Weaker states serve as one of reasons for an easier rebellion, since they lack capacity to effectively keep rebels in check. A country's geography may also contribute in wars since rebels can easily escape. 
Where a population holds significant grievances, governments can be reluctant to make concessions to violent groups if they were previously unwilling to submit to nonviolent pressure. If they are willing to make concessions, a resolution could be prevented due to commitment problems.
See also.
The Bottom Billion