If independence movements are given a legal path and engaged in negotiations, secession is much less likely to happen.

When Catalonia declared independence from Spain in October, it was the first time an elected government in Western Europe had declared independence from an unwilling host state since Ireland’s 1919 declaration of independence from Great Britain. Civil war did not follow Catalonia’s declaration as it did Ireland’s.

Deposed Catalan President Carles Puigdemont says he backed down from making the declaration effective because he wanted to avoid violence. As a result, Spain has reasserted its authority and imprisoned key figures in the independence movement, but polls show Catalans’ support for independence has only risen.

Meanwhile, in Iraq, the Kurdistan Regional Government held a referendum on independence, which had a high turnout and passed overwhelmingly; the Iraqi government responded quickly with military force, defeating Kurdish forces and driving them back from disputed territory.

How should central governments treat independence movements? My own research shows that central governments can limit the uncertainty and violence over secession campaigns when they provide a legal path to independence. The most recent scenes in Catalonia and Iraqi Kurdistan only serve to further confirm this finding. When central governments crack down on independence movements, political and economic instability and even violence are the usual outcomes.

There are two major reasons why suppressing secession attempts by force is no solution to the issue. First, it is impossible to efface the dream of independence from people’s minds. Repression raises latent support for independence, even if it removes all public expression of that support. If the state eventually faces a moment of weakness or crisis, that latent support could quickly break out into a mass movement, as happened in various parts of Yugoslavia and the Soviet Union in the 1990s.

Second, when governments try to eliminate the possibility of independence, they give themselves a freer hand to mistreat their ethnic minorities. My research shows that democracies that define themselves as “indivisible” in their constitutions are less likely to decentralise power to their regions and give more rights to local communities to govern themselves.

If minorities around the world enjoyed a right to independence, few would exercise it.

In many countries, even democracies, the ethnic majority opposes the autonomy aspirations of minorities. Therefore, governments are tempted to recentralise power as a way of winning votes. The recent growth of Spanish nationalist parties such as Citizens (Ciudadanos) is just another example of this familiar phenomenon. The most effective way to restrain central governments’ centralising temptation is to give minorities an exit option.

If minorities around the world enjoyed a right to independence, few would exercise it. In most places with secession movements, evidence suggests only a minority of the population supports their aims.

Moreover, contrary to conventional wisdom, secessionism generally does not spread across borders. Some evidence suggests that self-determination claims are more likely to arise when there are more such claims in nearby countries, but no one has yet found that the success of independence movements in one country causes independence movements to become more successful in nearby countries.

Even within countries, independence claims often do not spread. If Catalonia were allowed to become independent, there is little chance that the Basque Country or Galicia would follow in the near future. Unlike Catalonia, the Basque provinces enjoy tax autonomy and are not heavily taxed for the benefit of the rest of Spain.

If governments permitted independence, they could negotiate the terms.

Moreover, Basque nationalists do not want to gain independence until all Basque territories support it, and the Basque region of Navarre has always shown weak support for independence. Galicia is politically conservative and enjoys net subsidies from the rest of Spain; independence is not a live option there.

If governments permitted independence, they could negotiate the terms. If Iraq had been willing to negotiate the terms of Kurdish independence, they likely could have won territorial concessions without the use of military force. If Spain had been willing to negotiate a binding referendum with the Catalan government similar to the British government’s deal with the Scottish government in 2014, they could have worked out a threshold of success (say, 55 percent) that would have made success unlikely.

A failed referendum could have ended the independence threat for a generation. Instead, by sending in thousands of riot police, jailing politicians and taking their assets, banning websites, pressuring and raiding private newspapers, print shops, and hotels, and prosecuting political expression by private citizens, they have alienated moderate Catalans, lost face internationally, and ensured that independence and related issues like “political prisoners” will remain on the agenda for the indefinite future.

Supporting a negotiated, democratic solution to independence controversies does not mean supporting independence. It simply means taking away some of the risks and costs of these disputes and allowing a normal debate on the merits of the issue to take place. Governments will treat all their citizens better when they know they cannot forever trap them into political subjection against their will.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial policy.