Understanding Civil War: Causes, Stages, and Historical Examples

When a state’s authority breaks down and groups within the same country take up arms against the government, the result is one of the most destructive forms of political violence: civil war. Unlike wars between nations, civil wars tear apart a single society from within, pitting neighbours, communities, and sometimes families against one another. They have become the dominant form of armed conflict in the modern world, far outnumbering wars between states. Understanding why they begin, how they unfold, and what happens after the fighting stops is essential for anyone studying peace and conflict. Let us break down the concept, its stages, and the lessons drawn from history.

What is a civil war? 🔗

At its core, a civil war is an internal societal conflict in which organised groups fight to either retain or capture political power. The American political scientist James Fearon offers a widely used definition, describing it as a violent conflict within a country fought by organised groups that aim to take power at the centre or in a region, or to change government policies. The key feature is that one side is usually the state itself, while the other is one or more non-state armed groups operating within the state’s own territory.

This sets civil war apart from other forms of violence. It is not a war between two countries, nor is it a simple riot or an act of terrorism by an isolated group. Civil war is distinguished from interstate conflicts, from communal violence that does not involve the state, and from state repression of individuals who do not form a cohesive group. What makes it “war” rather than ordinary unrest is the scale and organisation of the violence. Scholars often use casualty thresholds to mark this boundary, with one widely cited dataset classifying civil wars as conflicts producing more than a thousand battle-related deaths per year.

A defining characteristic of civil war is the use of violence and extra-legal means. The contesting group does not seek power through elections or constitutional processes. Instead, it operates outside the law, building armed capacity and challenging the state’s monopoly over the legitimate use of force.

Two broad types: secession and succession 🔗

Civil wars generally take two forms, and the distinction matters for understanding what the fighters actually want. The first is a war of secession, where a group fights to break away and form an independent country. The second is a war of succession, where a group fights to overthrow and replace the existing government. According to the Council on Foreign Relations, wars of secession occur when people fight to form an independent country, while wars of succession involve people fighting to overthrow ruling authorities. As we will see, the East Pakistan conflict was largely a war of secession, while many other internal wars are about capturing the centre.

Why do civil wars begin? 🔗

No single factor explains why a society descends into civil war. However, scholars have identified recurring conditions that make conflict more likely. The common thread is a combination of ineffective governance and unaddressed grievances that the political system fails to resolve peacefully.

The role of weak governance 🔗

States with fragile institutions, poor economic performance, and limited reach over their own territory are far more vulnerable. When a government cannot deliver basic services, protect its citizens, or include all groups in political life, it creates space for armed challengers. Analysts at Johns Hopkins have noted that politicians who make short-term deals to win elections can produce “predatory political environments” that create the conditions for violence, and that preventing this requires inclusive leadership and openings for economic growth.

The greed versus grievance debate 🔗

One of the most influential frameworks in conflict studies is the “greed versus grievance” debate. The grievance argument holds that conflicts erupt from genuine injustices: ethnic or religious discrimination, political repression, and economic inequality. Early scholars such as Ted Gurr emphasised how groups may rebel when they are dissatisfied with their economic status relative to their aspirations.

The greed argument, advanced by economists Paul Collier and Anke Hoeffler in a study for the World Bank, focuses instead on the opportunity and ability to finance a rebellion. Their analysis found that dependence on primary commodity exports and the presence of a large diaspora substantially increase the risk of conflict, while greater ethnic and religious diversity actually reduces it. In simple terms, rebellions are more likely where they can be funded and where the state is too weak to stop them.

In reality, these motives are intertwined. Critics like David Keen argue that greed and grievance feed each other: leaders may deliberately stoke grievances to build the popular support that helps them capture resources and power. For students, the useful takeaway is that almost every society contains some grievance, yet very few experience civil war. The difference often lies in whether armed rebellion becomes feasible, not just desirable.

Is civil war planned or spontaneous? 🔗

Civil wars can emerge in two ways. Some are spontaneous, erupting suddenly from a triggering event such as a contested election, a massacre, or a natural disaster that exposes government failure. Others are planned, the product of years of careful organisation by a determined movement that builds its strength before striking.

Most major conflicts contain elements of both. A long-simmering grievance creates the underlying conditions, while a single dramatic event lights the spark. The 1970 Bhola cyclone in East Pakistan is a good example. The disaster killed hundreds of thousands of people, and the minimal relief effort from West Pakistan deepened resentment that fed into the wider independence movement. The grievance was old; the trigger was sudden.

The operational stages of a civil war 🔗

While every conflict is unique, civil wars and insurgencies tend to move through recognisable stages. Understanding this progression helps explain how a small armed movement can eventually challenge an established state.

Stage one: building a resistance structure 🔗

In the first stage, the movement focuses on organisation rather than open fighting. Leaders recruit members, establish a command structure, secure funding, and build networks of support among the population. This is often done quietly, away from the state’s attention. Without this hidden foundation, an armed challenge cannot survive the state’s superior firepower.

Stage two: applying violence 🔗

Once a structure exists, the movement begins to apply violence. This typically starts with smaller actions such as ambushes, sabotage, assassinations, and guerrilla attacks, gradually escalating as the group gains strength. The goal at this stage is to weaken the government’s authority, demonstrate that the state cannot guarantee security, and win further support or control over territory.

Stage three: publicly gaining power 🔗

In the final stage, the movement openly contests control. If successful, it captures the centre of government or carves out a region it governs directly. This is where the conflict’s outcome is decided, either through military victory, the collapse of the existing state, or a negotiated settlement.

Historical example: the war in East Pakistan 🔗

The 1971 conflict that gave birth to Bangladesh is a powerful case study, particularly relevant to readers in this region. After Partition in 1947, Pakistan was created as two wings separated by over a thousand miles of Indian territory, with East Pakistan being Bengali-speaking and economically marginalised despite holding the larger population.

The underlying grievance was the sense that East Pakistan was treated as a colony by the West. This boiled over after the 1970 election, when the Awami League led by Sheikh Mujibur Rahman won a decisive majority but was denied power. The state’s response was not negotiation but force. On 25 March 1971, the Pakistan Army launched Operation Searchlight, a brutal military operation intended to suppress the Bengali independence movement, accompanied by widespread atrocities against civilians.

What followed fits the pattern of civil war closely. Bengali guerrilla fighters known as the Mukti Bahini organised resistance and waged a campaign against the Pakistani military. The conflict lasted around nine months, with death estimates ranging widely into the millions and around ten million refugees fleeing into India. The war ended on 16 December 1971 when Pakistani troops in East Pakistan surrendered, marking the formal establishment of Bangladesh. This example also illustrates an important reality noted by many scholars: civil wars are rarely purely domestic. India’s eventual military intervention transformed an internal conflict into an international one.

Historical example: the Sri Lankan conflict and the LTTE 🔗

Sri Lanka’s long civil war offers a contrasting and equally instructive case, this time closer to a war of secession driven by ethnic grievance. The conflict pitted the Sinhalese-dominated government against the Liberation Tigers of Tamil Eelam (LTTE), who sought an independent Tamil state called Tamil Eelam in the island’s north and east.

The roots lay in discrimination against the Tamil minority after independence in 1948. Policies that promoted the Sinhala language and imposed education quotas marginalising Tamils fuelled deep resentment. When peaceful political channels failed, some Tamils turned to armed struggle. The LTTE, founded by Velupillai Prabhakaran in 1976, gradually eliminated rival groups to become the sole representative of the Tamil cause.

The full-scale war is generally dated to July 1983, when anti-Tamil riots in Colombo known as “Black July” followed the LTTE’s killing of thirteen soldiers. The conflict then ran for roughly 26 years, marked by suicide bombings, assassinations, forced recruitment, and cycles of failed peace talks. At its peak around 2000, the LTTE controlled a large share of the landmass in the Northern and Eastern provinces. The war finally ended in May 2009 when government forces defeated the LTTE militarily. The outline describes the Sri Lankan conflict as ongoing, but it is worth noting that the armed phase concluded in 2009, even though the deeper grievances and the task of reconciliation persist.

The challenge after victory: from fervour to governance 🔗

Winning a civil war is not the end of the struggle. It often marks the beginning of a far harder task. A movement that succeeds in capturing power faces a difficult shift: the energy, idealism, and revolutionary fervour that mobilised people for the fight must now be channelled into the slow, unglamorous work of governing.

This transition is genuinely difficult. The skills needed to run a guerrilla campaign are not the same as those needed to build institutions, manage an economy, and deliver services. Fighters expect rewards, rival factions compete for influence, and the new authorities must suddenly defend the very status quo they once attacked. Bangladesh, for instance, faced the hard transition from conflict and gross human rights violations to building peaceful, stable, democratic governance and the rule of law. Many states that win their wars then slide back into instability because the underlying grievances were never truly resolved. Peace, in other words, is not simply the absence of fighting; it is the construction of a political order that people accept as legitimate.

Why civil wars matter today 🔗

Civil wars are no longer the exception in global conflict; they are the norm. They cause immense human suffering, displace millions, and can destabilise entire regions, as both the Bangladesh and Sri Lanka cases show through their effects on neighbouring states. They also tend to recur, with countries that have experienced one civil war facing a higher risk of another. This is why peace and conflict studies place so much emphasis not just on ending wars, but on addressing the governance failures and unresolved grievances that allow them to begin in the first place.

What do you think? If most societies contain some form of grievance yet only a few experience civil war, what do you believe is the single most important factor that tips a country over the edge into armed conflict? And given how hard the transition from fighting to governing has proven to be, should the international community focus more on preventing civil wars or on supporting states in the difficult years that follow them?

References

1. https://en.wikipedia.org/wiki/Civil_war
2. https://www.britannica.com/topic/civil-war
3. https://education.cfr.org/learn/reading/understanding-intrastate-conflict
4. https://washingtondc.jhu.edu/news/how-civil-wars-and-other-internal-conflicts-arise/
5. https://ora.ox.ac.uk/objects/uuid:f6463573-a4dc-460a-bdea-c9d5a3d7b17c/files/smk61rh18q
6. https://www.nationalarchives.gov.uk/education/resources/the-independence-of-bangladesh-in-1971/
7. https://www.britannica.com/event/Bangladesh-Liberation-War
8. https://www.ebsco.com/research-starters/history/tamil-separatist-violence-erupts-sri-lanka
9. https://en.wikipedia.org/wiki/Liberation_Tigers_of_Tamil_Eelam
10. https://irpj.euclid.int/articles/bangladesh-liberation-war-of-1971-decisive-role-of-india-in-mediation-and-conflict-resolution-and-transitional-justice-in-bangladesh/