The world’s newest country, South Sudan, is not only in the midst of a brutal civil war, it is also facing what has been characterised as “the world’s worst food crisis.”

While both sides in the conflict have attacked unarmed civilians in hospitals, churches and mosques and committed ethnically targeted acts of rape, a staggering two million people have been displaced from their homes.

This equates to about one in five people in a country where nearly everyone relies on subsistence farming, fishing or herding for their livelihoods.

Last month, just days before the collapse of regionally organised peace talks between South Sudanese President Salva Kiir and former vice president, now rebel leader, Riek Machar, the United Nations Security Council adopted a resolution that installed a system for imposing individual sanctions, including asset freezes and travel bans, on “leaders of any entity” in South Sudan who block peace.

Kiir and Machar are clear targets of the sanctions. Since fighting broke out in December 2013 when the Sudan People’s Liberation Army split along mainly ethnic lines behind the two leaders, at least seven ceasefires have failed and three peace agreements have been signed and broken.

The new resolution, which was drafted by the United States, does not impose an arms embargo but leaves the option open for one in the future.

Human-rights organisations have led widespread calls for an impartial arms embargo and the idea has been supported by many within the Obama administration, including Secretary of State John Kerry and ambassador to the United Nations Samantha Power, as reported by Foreign Policy earlier this year.

Thankfully, for now, the calls have gone unheeded. If the goal is to end the conflict and encourage a sustainable peace in South Sudan, the Security Council resolution is likely to help.

An arms embargo, on the other hand — or even the possibility of one — threatens perverse outcomes and should be taken off the table as soon as possible.

Given what scholars have learned about the causes of civil war, South Sudan is a tinderbox. The country has a rich base of natural resources, specifically oil in the states of Unity and Upper Nile where fighting has been concentrated.

It has weak (in fact, brand new) state institutions, extremely limited infrastructure to reach remote areas, and a history of past conflict (primarily with Sudan). At the same time, national income is very low and there are ethnic divisions that can be exploited for political gain.

Still, none of these factors, individually or combined, make conflict inevitable. That still takes a spark — which in this case was the split between Kiir and Machar.

Contrary to popular perceptions, the current conflict is not driven by ethnic hatred between the Dinka and Nuer but rather by the leaders’ willingness to politicise their power struggle along these ethnic lines.

Furthermore, Kiir and Machar authorise (either actively or passively) acts of horrific violence by their military factions. This dynamic instils fear among the civilians caught in the crossfire, which increases recruitment and drives the conflict forward.

The new sanctions programme will help pressure Kiir and Machar to reach a negotiated settlement by imposing private costs on them and their advisors for the continued fighting.

Until now, each has held out for the potential rewards of victory while the immense social costs of the war have been borne by ordinary South Sudanese civilians.

The Security Council should ratchet up pressure as the conflict drags on. At the same time, regional bodies should support settlements that would allow Kiir and Machar to save face, and international institutions like the World Bank should work to develop revenue management tools that could help a power-sharing government achieve staying power.

But what about the proposed arms embargo? Don’t fewer weapons imply less violence and a faster end to the conflict? Historically, the answer has been no and the reasons for this are quite clear.

In a 2005 study of past multilateral arms embargoes enacted by the Security Council during civil wars, Dominic Tierney concluded that their impacts ranged from irrelevant to malevolent.

He found that arms embargoes are rarely enforced, especially in Africa, and that even when enforced, they fail to force political changes in target countries and tend to have serious unintended consequences. They strengthen more criminal networks within armed groups and, in the case of impartial arms embargoes, the impacts are never neutral.

When weapons are scarce to begin with, an impartial arms embargo may favour the sitting government, which has greater resources stockpiled. But in the case of South Sudan, which is flush with weapons from past conflicts, an impartial arms embargo would be likely to favour the rebels since the government’s supply lines stand to be more affected by the measure.

In this way, by simply holding out the potential imposition of an arms embargo in the future, the Security Council may already be working to lengthen the civil war. Machar probably sees little reason to settle for a peace agreement if a future arms embargo would strengthen his side.

Unfortunately, a prevailing assumption among many continues to be that African civil wars are the product of ethnic hatred and access to arms. In such a world, any initiative that decreases the availability of weapons is a promising step, and perhaps the only promising step, that can be taken by the international community. However, the world is much more complex.

As South Sudan enters its rainy season and 3.5 million people are expected to face a food security crisis or emergency — one step away from famine — the international community can actually do a great deal to help end the civil war in South Sudan. But at the same time, if diplomats ignore what has been learned through the study of civil war or the context of South Sudan itself, some efforts could easily do more harm than good.

Based on what is known about civil war in general and the conflict in South Sudan specifically, the current Security Council resolution is a step in the right direction. Meanwhile, the continued calls for an arms embargo threaten a big step back.

Tim O’Brien is completing his masters in public administration in international development at Harvard University’s John F. Kennedy School of Government.