With shells flying overhead, the Congolese soldiers pressed forward on a desolate stretch of road near the Rwandan border. Ahead of them was a rebel army, firing relentlessly. Behind them, a new U.N. combat brigade waited in white armored vehicles, ready to serve as backup.

The U.N. soldiers are in Congo with an ambitious goal: to reverse the trajectory of one of the world’s most horrific and complex conflicts, one that has killed more than 5 million people since 1998, the deadliest war since World War II. They are also here to rescue the image of the troubled U.N. peacekeeping mission in the Congo.

“To be a peacekeeper doesn’t mean you need to be passive,” their top commander, Gen. Carlos Alberto dos Santos Cruz, said hours before the offensive began. “To be a peacekeeper, you need to take action. The way to protect the civilians is to take action. If you see the history of atrocities here, it justifies action.”

Inaction is precisely what the U.N. mission here has been criticized for in the 14 years since the United Nations dispatched soldiers to Congo, the first members of what has become the largest peacekeeping force in U.N. history. Now, the U.N. Security Council has launched the Forward Intervention Brigade in a bold attempt to defeat the dozens of militias that pillage this mineral-rich central African country, which is roughly the size of Western Europe. The brigade, composed of 3,000 soldiers, is the United Nations’ first offensive combat force and is seen as a possible model for defusing crises in other chaotic parts of the world.

But the force is also an unparalleled gamble for the United Nations that challenges the basic principles of peacekeeping. It has orders to react offensively to enforce peace, essentially transforming peacekeepers into combatants. And it is openly supporting Congolese government forces, a move away from the principle of neutrality that has guided other U.N. missions.

That could affect the United Nations’ ability to negotiate peace deals with the militias and risks deepening conflicts. Humanitarian agencies are worried that Congo’s brutal militias could see the entire U.N. mission, which also includes aid workers, monitors and civilian experts, as non-neutral potential targets.

There are also concerns that the U.N. force is propping up a corrupt government and aiding an undisciplined military that has a history of human-rights abuses, including mass rapes. Many Congolese remain skeptical of the new brigade’s potential to eradicate the militias. Others have lofty expectations that could bring disappointment and further antagonism toward the U.N. mission.

But senior U.N. civilian and military officials, as well as some analysts, say the brigade could be the United Nations’ best chance to help bring meaningful change, and perhaps even a sustainable peace, to Congo.

This week, the Congolese and U.N. forces pushed the rebels of the M23 movement out of major towns, including their last primary stronghold of Bunagana, near the Ugandan border. The remarkably swift military defeat of the rebels, who only last year briefly seized the eastern city of Goma, represented the first significant victory for the force.

“Everybody is impatient,” said Martin Kobler, the special U.N. envoy to Congo. “The atrocities going on, the rapes of women and the use of child soldiers, this is just unacceptable. That’s why it’s a good development to have the intervention brigade here. This is teeth.”

Years of conflict

Congo has been plagued by conflict since the fall of its longtime dictator Mobutu Sese Seko in 1997 following an ethnic rebellion triggered by the 1994 genocide in Rwanda. A succession of rebel militias have fought over the eastern part of the country, bordering Rwanda and Uganda, and its valuable resources, including vast deposits of tin, gold and coltan, an ore that yields elements used in cellphones and laptops.

In 1999, the United Nations launched an observer mission here. Confronted with a bloody conflict that became known as Africa’s first “world war,” involving nine nations and dozens of rebel groups, the mission was steadily enlarged and its mandate expanded. But the peacekeepers remained unable or unwilling to prevent rebel groups from killing, raping and terrorizing the population or from seizing entire towns in eastern Congo.

“The population was expecting a solution from the U.N. for many years, but there was not even the beginning of a solution,” said Gautier Muhindo Misonia, a human rights activist and president of a collection of local nongovernmental organizations.

Kobler said that without the peacekeepers, the country would have been gripped by more violence and instability. The primary responsibility for bringing peace, he said, lay with the Congolese government.

For more than a year, the highest-
profile rebel militia has been the M23 movement. It was launched in April 2012 by disaffected Congolese soldiers who wanted the government to honor the terms of a 2009 peace deal following a previous rebellion. U.N. investigators allege that Rwanda is financing and arming the rebels, who are mostly Tutsis, the same ethnicity as the Rwandan leadership. Rwanda has publicly denied the allegation.

Last year, several hundred M23 rebels seized Goma for 10 days before withdrawing voluntarily, embarrassing the U.N. mission. That prompted France’s foreign minister to declare it “absurd” that 17,000 U.N. soldiers could not protect the city, and he urged a review of the U.N. mandate. Massive demonstrations erupted in Goma, and U.N. vehicles were stoned. On Twitter, critics began referring to the mission, whose name is abbreviated in French as MONUSCO, with the hashtag #MONUSELESS.

The capture of Goma prompted the U.N. Security Council to approve the intervention brigade this year, giving it a mandate to “neutralize” all of Congo’s militias. The force, made up of troops from South Africa, Malawi and Tanzania, became operational this summer. In late August, the brigade went into action for the first time, backing Congolese government forces by firing artillery shells at M23 rebel positions a few miles north of Goma in the town of Kibati. The fighting drove the rebels back a few miles, preventing them from shelling Goma and convincing them to enter peace talks in the Ugandan capital, Kampala, in September.

Still, many Congolese are unconvinced that the brigade, known as FIB here, would be different from other U.N. peacekeeping forces. Two days after the Kibati clashes, an angry crowd stormed the U.N. mission’s base in Goma claiming the United Nations had not done enough to protect them. Two protesters were killed in the chaos and a U.N. car was reportedly set on fire.

During a routine patrol last week through the streets of Goma, the intervention brigade was taunted by residents: “You have no job. You have no job.”

“The population is questioning whether 3,000 soldiers from the FIB can do a job that 17,000 U.N. peacekeepers have failed to accomplish,” said Danny Kayege, a historian. “The population does not have any confidence in them.”

In Kilimanyoke last week, some Congolese soldiers dismissed the new brigade’s fighting capabilities. “They stand behind us and shell. But we are the ones fighting on the front line, face to face with the enemy,” said Jean Luc Basunga, a Congolese government soldier. “Even if the FIB doesn’t help us, we can defeat the enemy.”

But in a visit to Kibati last week, most residents interviewed said the new brigade was more committed to protecting them than other U.N. peacekeepers have been.

“The FIB is not like the other MONUSCO soldiers,” said Nsengiyunva Mudyango, 35, a farmer, standing near several destroyed houses. “I see they are strong, and here to help us.”

More challenges ahead

Even with the capture of Bunagana and the possible demise of M23 as a military force, many challenges remain for the intervention brigade and the U.N. mission. The country’s political institutions are crumbling, corruption and poverty are widespread and ethnic divisions run deep.

U.N. officials say a political solution is still the best path forward, but in a phone interview last week, Amani Kabasha, the rebels’ political spokesman, said his group had lost trust in the U.N. mission because it was supporting Congolese forces. “Even if they kill all of the M23, another group will rise in our place,” he warned.

The intervention brigade is expected to go after more than 40 other militias who are committing atrocities, stealing Congo’s mineral wealth and preventing the government from functioning — a task that seems virtually impossible. There is also the problem of perception. The Enough Project, a human-rights group, said in a report last week that the brigade “risks being seen, or being used, as a pawn of Kinshasa,” the capital.

Both Kobler and Cruz said the brigade would not work with any Congolese army units that have committed human-rights abuses. They also said the brigade would work at times on its own.

U.N. and other humanitarian aid workers said in interviews that they remain worried about the new brigade.

“The presence of the FIB is a problem for all the humanitarian actors,” said Francesca Mangia, the head of Doctors Without Borders France in Goma. “When the population sees a white car, they don’t differentiate between whether it is us, the U.N. or FIB. It makes us military targets. “

Near the front line, the significance of their mission was not lost on members of the intervention brigade. Maj. Vic Vrolik, their South African commander, said that eliminating the M23 was the first step to “start concentrating on the other armed groups.”

“If we succeed, it will show that the U.N. can solve problems in war-torn areas,” he said.