On Jan. 10, three years after Northern Ireland’s main political parties suspended its power-sharing assembly and government, the parties agreed to return to governing. What prompted this dramatic shift?

The assembly and government were fundamental elements of the 1998 Good Friday/Belfast Agreement that brought peace to Northern Ireland. However, they collapsed in 2017 amid arguments between the province’s two largest parties: the Democratic Unionist Party (DUP), whose members are predominantly Protestant and want Northern Ireland to remain part of the United Kingdom; and Sinn Fein, whose members are predominantly Catholic and want Northern Ireland to unite with the Republic of Ireland. What kicked off the dispute was the Democratic Unionist first minister’s involvement in a scandal related to mismanagement of public funds. But uncertainty about the 2016 Brexit referendum complicated matters, as each party sought potential advantage over the other.

So why have they agreed to resume the government after having refused to cooperate for three years? And what comes next for Northern Ireland?

Unhappy voters and the changing politics of Brexit changed politicians’ incentives

Without anyone to make the necessary decisions since 2017, bread and butter issue areas such as health and education have fallen into crisis. In December, for example, almost 20,000 health service workers went on strike over low pay, inadequate staffing levels, dangerous conditions and a declining quality of care. Citizens have put intense pressure on politicians to do the jobs for which they continued to be paid despite the suspension.

Furthermore, the politics of Brexit changed the political parties’ calculations. From 2017 until the U.K. Parliament’s December elections, the DUP enjoyed power as junior partner to the Conservative Party. However, the DUP was less influential than it had hoped; it was unable to prevent the British Parliament from extending same-sex marriage and abortion rights to people in Northern Ireland, despite its strong opposition. Perhaps more important, the DUP also failed to prevent Boris Johnson’s government from approving a Brexit withdrawal deal that will leave Northern Ireland tied to the Republic of Ireland’s economy and that of the European market — while creating trade barriers between Northern Ireland and the rest of the United Kingdom.

The new U.K. government no longer depends on the DUP, as the Conservative Party won an outright majority. It declared that it would call new elections in Northern Ireland if the parties did not find common ground by Jan. 13. In the December U.K. elections, both Sinn Fein and the DUP lost votes to more centrist parties, so they had no appetite to face the voters again without making progress on issues that matter to them.

The British House of Commons also passed Johnson’s withdrawal deal Jan. 9 — suggesting that the U.K. is now very likely to exit the European Union on Jan. 31. Northern Ireland now needs locally accountable politicians to represent its interests throughout the transition, making the significant decisions about implementation that remain.

Now the governing parties will have to deal with ordinary politics

For the past three years, government ministries have been running on autopilot. But now the DUP, Sinn Fein and the three other, smaller parties in the executive will have to deal with the backlog of neglected issues. They face pressure to reform the health care, education and welfare systems; invest in infrastructure and public services; address policing issues leftover from the Troubles; and devise new funding schemes to pay for all of this, possibly by taxing water. These mundane politics of governing are all complicated by the fact that the parties have multiple, competing agendas and little experience of trust or cooperation.

The parties will also have to deal with the politically vexed question of language politics — specifically, the status of Irish (a Gaelic language) and Ulster Scots (a Scots dialect that is related to English) as official languages. Although Lithuanian and Polish are, after English, the most common first languages spoken in primary schools, the Irish and Ulster Scots languages are important symbols of culture and identity for nationalist/Catholic and unionist/Protestant identities respectively. Indeed, the DUP’s refusal to back the Irish Language Act, which would have recognized the Irish language as an official language in Northern Ireland, was almost as central as the public works scandal was to the 2017 collapse of government.

As part of the agreement to go back into government, both parties agreed to support legislation that would create an Office of Identity and Cultural Expression and appoint commissioners to enhance the development of both languages, although in slightly different contexts: the use of Irish by public authorities and the use of Ulster Scots in arts and literature. Given that the two sides have been wrestling over the language issue since 1998, if not before, working through the details and implementing the legislation will be challenging.

Further, the multi-party government will have to decide what Boris Johnson’s Brexit deal will mean for trade within and from Northern Ireland. For now, Northern Ireland will remain in the E.U.’s regulatory framework
— while goods coming from Northern Ireland into the rest of Great Britain will have to go through customs checks. That sign of separation from the U.K. troubles the DUP. The Northern Ireland parties will have to agree whether to make that permanent or find some other solution to prevent a hard border between Northern Ireland and Ireland, which would antagonize Sinn Fein and threaten to reignite the Troubles. They will also have to work with the British and Irish governments on the details of hundreds of separate and related matters.

All of this comes amid fundamental changes to Northern Ireland itself. Changing demographics are making Irish unification more plausible in the near term, as nationalists, who wish to have Northern Ireland leave the U.K. and unite with the Republic of Ireland, become more dominant. Nationalists make up a majority of legislators in Northern Ireland for the first time. If the government were to hold a referendum on unification, as the Good Friday Agreement provides for, polls suggest that unification would pass with a slight majority. There is no guarantee that such a referendum will take place, or would pass, but even the possibility could reignite tensions or even lead to violent conflict between the communities.

Kimberly Cowell-Meyers is assistant professor in the School of Public Affairs at American University.

Carolyn Gallaher is senior associate dean in the School of International Service at American University.