A woman and her son celebrate the signing of a historic cease-fire deal between the Colombian government and the Revolutionary Armed Forces of Colombia in Bogota, Colombia, in June 2016. (Reuters)

This week the Revolutionary Armed Forces of Colombia (FARC) is introducing its political party. The U.N. Security Council also recently unanimously approved a resolution authorizing a mission in Colombia that would run through the 2018 elections in which FARC candidates will compete.

The Colombian government and the FARC struck a peace deal in 2016, ending decades of conflict. The transition to normal politics and the outside verification of that process taking place now are part of that deal. The approval process hit a number of obstacles, however, and challenges remain on how to implement an overhaul of land and rebuild a stable society. Will the elections in 2018 in Colombia cement the peace?

The FARC’s transition from rebel group to political party is a promising sign. My new book shows that rebels now agree to participate in post-conflict elections in almost half of all cases. My research also shows that these elections are critical to bringing an end to the conflict and building an enduring peace.

Post-conflict elections with rebel parties let outside actors help enforce the rules

Other types of peace settlements may also seek to construct a stable distribution of power between the warring factions and even foster legitimacy. But peace agreements that spell out electoral participation are different in a surprising but important way: They foster external engagement. The United Nations and other outside actors can play an important role in making sure all former warring factions respect the terms of the peace agreement.

This is important, as former combatants are likely to be concerned that their opponents will violate the terms of the settlement over time. In implementing a settlement, relative power inevitably shifts between the sides — for example, when the rebels have disarmed but not yet taken up positions in the state structures, which is where the FARC currently finds itself in Colombia, they will now be weaker compared to the government.

The stronger side has incentives to take advantage of those moments to seize even more benefits than those provided by peace. The existence of incentives for noncompliance, which can cause conflict to recur, or even cause the concerned side not to sign a settlement at all, can be resolved if outside actors punish violations.

Outside actors’ threats to reward and sanction, however, must be credible. These third parties need information to tell whether both sides are following the terms of the settlement, as well as leverage that they can use to punish any noncompliance with those terms. In some cases, outside actors can credibly threaten to use force.

More often, even if peacekeepers are on the ground, the mandate of the mission and the resources provided do not allow for the use of force. Not to mention that the transgressions may involve subtle means to seize slightly more power — for example, changing where polling stations are placed — so, if detected, these transgressions generally would not merit punishment by force.

Outside intervention — without the use of force

As democracy promotion programs spread, these outside actors, usually the United Nations and donor countries, have used election observation and aid related to the elections to monitor and encourage compliance by all parties. So including former rebel groups in these elections allows for outside intervention without the use of force.

In conjunction with peacekeepers, or even without a peacekeeping mission, observers around elections have often provided information about whether the former warring factions are distributing power as they agreed.

In El Salvador, for instance, the government attempted to move polling stations in former rebel strongholds to the department capitals, effectively reducing the vote share of the FMLN, the former rebel party. But U.N. teams disputed the government’s security rationale for doing so, and the policy was reversed.

This kind of stabilizing external engagement can persist. In Bosnia, for example, the European Union has judged elections that occurred decades later, using benchmarks set in the 1995 Dayton Accords.

These outside actors also provide incentives for combatants to continue to peacefully participate in these post-conflict elections. Since the Cold War, international assistance to post-conflict states — including development aid and, increasingly, democracy and governance assistance — were at times conditioned on compliance with the terms of peace deals.

Many peace deals also include trust funds or other assistance for former rebel political parties, so that all sides face the threat of sanction, and even small reductions in resources can have effects. For instance, Renamo, a rebel group in Mozambique, considered reneging, but the threat of losing a substantial trust fund kept it participating peacefully.

Over time, these incentives are applied for former warring factions. In El Salvador, donors working alongside the United Nations threatened to withdraw aid from the government when force demobilization came more slowly than the terms of the peace agreement. The government had strong incentives to comply, given the likely effect that losing that aid would affect its own electoral chances. After the rebels failed to report all of their weapons, the U.N. team also threatened not to allow their campaign activities, producing quick compliance. Data collected across all elections, as well as these post-conflict elections specifically, also shows outside actors’ willingness to invoke conditionality around elections.

An enduring peace is more likely when outside actors are involved

Civil conflicts are deadly, often resulting in more deaths than conflicts between states in the modern era. Peace agreements are difficult to secure — and civil conflicts can recur as concerned combatants scramble back to the battlefield at the first hint of noncompliance.

When deals provide for rebel parties to participate in post-conflict elections, my research shows that peace holds 80 percent more frequently. The stabilizing effect is strongest when external engagement is especially likely.

Just holding an election is not enough. Rebel parties must participate in post-conflict elections that distribute power between the former warring factions, and external actors must also work through the elections to monitor and enforce the terms of settlements for all sides. However, in contrast to existing studies that show more mixed results of post-conflict elections, my research suggests that post-conflict elections in which rebel parties are set to participate can help produce enduring peace.

Despite the many challenges in Colombia, the FARC’s transition from rebel group to political party ahead of the 2018 elections is a positive step in this peace process. With the United Nations and other outside actors set to engage around the elections, the country may be on the path toward peace.

Aila M. Matanock is an assistant professor of political science at the University of California at Berkeley. Her new book, “Electing Peace: From Civil Conflict to Political Participation,” is published by Cambridge University Press.