A crowd of protesters gather outside the Catalan region’s economy ministry building in Barcelona on Sept. 20. (Manu Fernandez/AP)

Controversial referendums on independence are scheduled in Iraqi Kurdistan on Sept. 25 and the Spanish region of Catalonia on Oct. 1. Both referendums place these secessionist regions on a collision course with their central governments and the international community, increasing the probability of conflict. What is the purpose of these referendums, and what is the strategy behind them?

Secession occurs when a region within a state breaks away to form its own sovereign state. There were 55 active secessionist movements around the world as of 2011, and an average of 52 movements per year since 1945. Most have failed to achieve their goal of independence, sometimes coming to an agreement with their central government or simply fading away. Roughly a third have resulted in violence. Indeed, some claim that secessionism is the chief cause of violence in the world today.

As I argue in my recent book, we are truly living in the Age of Secession.

Strategy of secession

The Kurds and the Catalans are pursuing the same overall strategy of secession. Strategically, all secessionist movements are the same: they need to make a change by forcing others to recognize them as independent states. To do so, they engage in “compellence,” getting an actor to do something they would not otherwise do. These tactics vary, from the deployment of violence to civil resistance to electoral competition. Seen from a wide angle, Catalonia and Iraqi Kurdistan are not unique. They are using the same strategic playbook and employing the same tactics as other movements of their kind.

A secessionist movement can take two approaches to achieving independence. The first is to target their central government, the chief obstacle to any movement for achieving independence. If the government permits the independence, as Serbia did for Montenegro in 2006, then the path to sovereign statehood is almost certainly guaranteed.

The second approach is essentially an end-run. Here, the movement goes around the central government to bring the international community into the game. As in South Sudan, the international community can either pressure the central government to permit the independence or, as in Kosovo, it can bypass the central government entirely to recognize the secessionist region. Most secessionist movements use both approaches.

How secessionist groups learn and weigh risky behavior

Secessionist movements are surprisingly aware of the strategic playing field. In interviews with more than a dozen secessionist movements, I have found that they are well networked and learn from one another. The Catalans sent observers to Scotland in 2014 to learn how to run a referendum campaign. The High Representative of the Kurdish Regional Government (KRG) to the United Kingdom used to meet regularly with their counterpart in the Catalan and Flemish movements to discuss best practices.

However, this does not guarantee secessionists will always prevail or even make the right tactical choices. Sovereign states are generally — though not always — opposed to secession because of its disruptive potential. Forcing them to negotiate requires confrontational and risky behavior that can alienate supporters or result in violence.

Such behavior is quite evident in both the Catalan and Kurdish cases. Should they be held, both referendums will increase tension with their central governments and the international community, raise the risk of conflict and potentially backfire. But strategic logic still motivates each group’s behavior.

Catalan secessionism

A secessionist region like Catalonia is shaped predominantly by the democratic institutions of the Spanish state. The chief compellence tactic is electoral capture — gaining control of the Catalan parliament and regional government (the Generalitat) to enact legislation that advances the cause of secession and forces the Spanish state to negotiate.

The upcoming referendum is intended to force the Spanish government to respond. Ignoring the referendum is risky. Since many “no” voters are expected to stay home, a “yes” vote could likely win. Moreover, the Catalan secessionists have promised to declare independence within 48 hours should they win the referendum. Sooner or later, the Spanish government will have to respond.

Obstructing the referendum or arresting participants — as the government has threatened to do — could make matters worse, possibly spurring unrest, civil disobedience and financial market uncertainty. Catalan secessionist leaders think at some point the international community, particularly the European Union, will be forced to apply pressure on the Spanish government to negotiate. An overreaction or crackdown by the government would only call further attention to the problem and invite external pressure.

Kurdish secessionism

Iraqi Kurdistan is somewhat different. The democratic institutions of the Iraqi state are weaker, the region is beset with violent conflict and the prospect of Kurdish independence is a concern for neighbors like Turkey and Iran, which possess their own Kurdish minorities. In a movement such as this, compellence tactics can include electoral capture, civil resistance and the use of violence.

The upcoming Kurdish referendum is aimed at both the Iraqi government and the international community. A strong “Yes” vote would strengthen the hand of the KRG in future negotiations for increased autonomy and full independence.

The international community plays a particularly large role in this case, given the politics of the region. The United States does not currently support the Kurdish referendum, saying that it is ill-timed and creates a distraction from the war with the Islamic State. But the Kurdish leadership thinks that the conflict gives them leverage to force the issue now when they are an important element of the war effort, rather than later when their demands will be easier to ignore.

Both movements are using strategic logic designed to compel key actors to make a change. It could work, but it could also backfire and result in violence.

Ryan Griffiths is a senior lecturer at the University of Sydney and the author of “Age of Secession: The International and Domestic Determinants of State Birth,” (Cambridge University Press, 2016).