Displaced people arrive in Awerial, Lakes State, by river barge from Bor town in December2013. Tens of thousands of people fled fighting between government and rebel forces in Bor to an impromptu camp in Awerial or to other locations in South Sudan.

© 2014 AP Photo/Ben Curtis

In Juba, South Sudan’s hot and dusty capital city, humanitarian organizations are bracing for the worst. With the end of the rainy season and roads drying up fast, fighting has already resumed between government forces loyal to President Salva Kiir and forces loyal to opposition leader, Riek Machar.

Both sides have had plenty of time to regroup, rearm, and prepare for the next round. Despite ongoing peace talks in Addis, fighting broke out around the UN base in Bentiu last week, killing one child and injuring 4 people on the base. Days before, the two sides clashed in Upper Nile State.

Abuses against civilians have been horrific and widespread. Many of the thousands killed since the conflict began in December were deliberately targeted because of their ethnicity or perceived allegiances. With no one yet held accountable for those crimes, there is no reason to believe that this time around civilians will be spared.

To make matters worse, South Sudan is already arguably the worst humanitarian crisis in the world. Famine has been barely averted this year but could come back with the fighting, humanitarians warn.

At the main UN base in Juba, close to 11,500 people - mostly Nuer, the tribe that Riek Machar belongs to - live in a refugee camp behind barbwires, fearful what waits for them outside the compound. Women who leave the camp looking for food risk being raped.

Two weeks ago, according to a humanitarian worker, a 15-year-old Nuer boy went out looking for mangoes in Juba’s Konyo Konyo market. He was caught by Dinka men – the ethnic group of President Kiir -  who put 3 nails in his skull, leaving him for dead. He survived only because a Dinka man found him, and in one of these acts of humanity you still encounter, brought him back to the UN camp where he was treated.

Ethnic tensions are palpable even in the capital. One of the few Nuer officials still working for the government told us that many of his Nuer colleagues are living in hotels where they feel safer. Despite their government’s protection, they can’t go out after dark or in certain neighborhoods for fear that their tribal Nuer markings could get them killed.

Journalists or activists who do not toe the government line are increasingly harassed and threatened. Newspapers have been seized and an editor who recently featured a front page picture of Machar was called in for questioning and intimidated by the national security service. Last month, the parliament passed a law allowing the National Security Service to arrest and detain without proper judicial oversight.  

Sadly, the newest country on earth is fast sliding toward an authoritarian and abusive rule strangely reminiscent of Sudan, the country that South Sudan broke away from in 2011.

The UN Security Council should impose an arms embargo on the country before it’s too late. The risk that new weapons will fuel more human rights violations is intolerable. Washington, which helped birth an independent South Sudan, should take the lead. This should be achievable, as even China seemed embarrassed when news broke over the summer that Chinese arms had been shipped to the government.

Until real accountability comes, leaders who are responsible for grave human rights violations should at least face the sanctions that can easily be applied now, such as a travel ban and an asset freeze.

With political will, these two measures could be adopted within a few days, sending an unmistakable message to both sides, before time runs out.