"Sudan is at the center of long-lasting permanent crises. It is characterized by frequent armed conflicts," Marina Peter, founder of the Sudan and South Sudan Forum, told DW.

"When a conflict breaks out in one of these countries, be it Egypt, Libya, Chad, the Central African Republic, South Sudan, Ethiopia, Eritrea or — looking across the Red Sea — Saudi Arabia, the neighboring country is always affected as well."

For the last week in Sudan, already politically unstable for years, the two most powerful generals and their units have been fighting for control. The outbreak of violence between forces loyal to the head of the army — Abdel-Fattah Burhan, the country's de facto ruler — and his deputy, Mohammed Hamdan Dagalo, known as Hemedti, who commands the paramilitary RSF group, only increases the risk of destabilizing the region, said Peter.

South Sudan worries about oil revenue

All of these countries depend on good relations with Sudan, she added, but especially South Sudan, which declared independence from Sudan in 2011. Since then, different ethnic groups have been vying for power, sparking a civil war in the young state in 2013 that resulted in hundreds of thousands of deaths.

Of the approximately 11 million South Sudanese, several million have been internally displaced or fled to neighboring countries. The war has been officially over since 2020, but peace is fragile. "To this day, there is still fighting between rebels in various places in South Sudan," said Peter.

Still, a shared history strongly connects people in both countries, said Gerrit Kurtz from the Africa and Middle East research group at the German Institute for International and Security Affairs in Berlin. "Many people from both countries live or stay in each other's countries, including refugees, and of course there are also close political and economic ties," Kurtz told DW.

South Sudan relies on foreign currency from crude oil sales, which comprises around 95% of public revenue, he added. Sudan is crucial to these exports, as the oil pipeline runs through Sudan to a port on the Red Sea. The government of South Sudan, therefore, has a strong interest in ensuring that this connection remains in place, said Kurtz.

But the government is itself at odds — a situation in which RSF leader Dagalo has previously acted as a mediator. "And now that this is no longer the case, and somehow the South Sudanese parties are also trying to position themselves with regard to the conflict in the north, this could now also lead to explosions of violence in South Sudan," said Kurtz.

'Humanitarian crisis' in Chad

Despite reports that Chad's military disarmed 320 paramilitary fighters from Sudan who had crossed the border on April 17, it's now mostly civilians who are on the move. Refugees from contested areas in western Sudan have already arrived in Chad, the country's Communication Minister Aziz Mahamat Saleh told DW. And this is despite the fact that the 1,500-kilometer (930-mile) border with Sudan has been closed.

Chad has a culture of hospitality and cannot hermetically seal its border, said Saleh. "We appeal to international partners to support us in this humanitarian crisis on the horizon," he added.

The country is already hosting more than 500,000 refugees, he said, adding that he fears an ongoing war could have a lasting impact on the entire Sahel region, including trade between the two neighbors.

Traditionally, there has been a lot of border traffic between Chad and Sudan, such as the flow of herders grazing their flocks on both sides of the border. While relations deteriorated during the Darfur conflict, they have since recovered.

Sudan's neighbors share common interest in stability

Egypt also has a long history with Sudan, and not just as a trading partner. Way back in the Pharaonic era, Sudan was part of Egypt and called itself Nubia. For a short time, however, the Nubians also ruled Egypt, and later both countries were under British colonial rule.

Egypt and Sudan have similar cultures, and the relationship of some Sudanese elites is close with Egypt, said Kurtz. "Many have studied in Egypt and the armed forces have been trained there or have had regular training in Egypt," he said. When the recent conflict broke out, members of the Egyptian Air Force were in Sudan for training. According to Sudanese officials, 177 were evacuated back to Egypt.

The military regime in Egypt tends to see Sudan's military government as an ally. "Relations are close, especially on the side of the armed forces and the military," said Kurtz.

Another factor is the dispute over Nile River water, which has become more acute since Ethiopia began damming upstream to power its giant GERD hydroelectric plant. Egypt wants to "bring Sudan into its own camp in the conflict," said Kurtz. There have been halting negotiations between the three nations for years, but a treaty hasn't materialized.

Even with such uncertainty in the background, early in the current conflict between Sudan's military and the RSF, Egypt and South Sudan both offered to mediate — further proof that Sudan's neighbors have a common interest in its stability.

This article originally appeared in German.