NAIROBI — The United Nations has dispatched a record number of peacekeepers in Africain recent years, deploying soldiers to trouble spots such as the Central African Republic and South Sudan. Yet the “blue helmets” and thousands of other soldiers sent by African regional groups have failed to prevent fresh spasms of violence.

The peacekeeping forces have cost billions of dollars, largely paid by the United States and European nations. But they have been hobbled by weak mandates and a shortage of manpower and equipment. Some critics also say Washington, its allies and U.N. officials are at fault in the peacekeeping failures, for not following through with enough political pressure to prevent crises.

(Ben Curtis/AP) – A U.N. armored vehicle passes displaced people walking towards the U.N. camp where they have sought shelter in Malakal, South Sudan,

“The political and diplomatic elements of the international response to most Africa conflicts have been slow and ineffective,” said John Prendergast, a longtime Sudan and South Sudan activist with the Enough Project, a human rights group. That, he said, “has put more pressure on peacekeeping missions to fulfill objectives for which they are totally unprepared.”

In South Sudan, a power struggle that U.S. and U.N. officials were aware of for more than a year has now sparked an ethnic and political conflict that has killed hundreds, raising fears of a potential civil war.

On Friday, the warring sides held their first round of peace talks in neighboring Ethi­o­pia, but the conflict showed no signs of abating. The U.S. State Department evacuated more of its embassy staff from the South Sudanese capital, Juba. Meanwhile, the rebel forces, which recently seized the strategic town of Bor, remained in a standoff with government troops, raising concerns that battles could flare up at any moment.

Already, nearly 200,000 people have been displaced by the fighting.

Frustration with the peacekeepers is rife. Ibrahim Muhammed, 30, fled the volatile Sudanese region of Darfur a year ago and arrived in South Sudan searching for a better future. Today, he languishes inside a U.N. peacekeeping base in the war-ravaged South Sudanese town of Malakal, living in a tent made of blankets.

“The U.N. peacekeepers have not been able to stop the violence in Darfur, and so I came here,” said Muhammed, a shopkeeper, in an interview last weekend in Malakal. “But in South Sudan now, the situation is similar to Darfur. It is tribe against tribe. The peacekeepers won’t be able to stop the attacks.”

Toby Lanzer, a senior U.N. official in South Sudan, conceded there are limitations to what peacekeeping forces can accomplish in trouble spots. In many situations, including South Sudan and the Central African Republic, U.N. and African forces lack resources and a sufficient number of soldiers, he added.

“There’s always a temptation when people hear of 5,000 or 10,000 peacekeepers for them to think that they can do an awful lot of good, and they can,” said Lanzer, the deputy special representative for the U.N. mission in South Sudan. “But what they cannot do is stabilize a situation in a whole country that is erupting into violence.”

Constrained by mandates

There are now more U.N. peacekeepers in Africa than at any time in history — roughly twice as many as in the early 1990s.

U.N. forces have often been limited by mandates that only allow them to fight in self-defense. Shortly before genocidal attacks erupted in Rwanda in 1994, for example, U.N. peacekeepers learned that arms were being imported illegally by an ethnic Hutu militia. But senior U.N. officials ordered the peacekeepers not to seize the weapons because it was outside the scope of their mandate, their commander, Brig. Romeo Dallaire, later recounted in a book.

More than two years ago, the U.N. mission in South Sudan was authorized to have up to 7,500 military personnel and police. But it was unable to stop the ethnic and political bloodletting that had been occurring since the country won independence from Sudan in 2011. In January 2012, the U.N. mission was heavily criticized by victims and community leaders for doing little to stop a wave of tribal killings in Jonglei State, the same region that is now a battle zone.

It was only after violence quickly spread across South Sudan in mid-December that the U.N. Security Council unanimously voted to nearly double the force to a little more than 14,000. But the peacekeepers’ mandate is framed in terms of development, “as if the problems of South Sudan were merely due to the lack of material aid, as opposed to rooted in deeper conflicts,” said J. Peter Pham, executive director of the Atlantic Council’s Africa Center.

“While one has to be realistic — and acknowledge that the U.N. and the African Union are not panaceas and not every conflict can be foreseen, much less prevented — one should also ask what the purpose of deploying some 7,000 troops from more than 60 countries to South Sudan at the cost of close to $1 billion a year is, if they are not keeping the peace,” said Pham.

But others say that if the peacekeepers were not deployed, there would have been more chaos and deaths in South Sudan, the Central African Republic and in other nations where poverty, poor governance and corruption have fueled violence.

“ I think one can legitimately criticize peacekeeping operations for not doing enough,” said E.J. Hogendoorn, deputy Africa director for the International Crisis Group, an independent organization that tries to prevent conflicts. “But without the physical intervention of either U.N. or African peacekeepers, those conflicts could oftentimes have escalated much more.”

 Lanzer, the U.N. official, said that the U.N. forces have helped keep most of South Sudan relatively stable, noting that much of the chaos and violence is unfolding in four of the country’s 10 states. The U.N. mission, he added, is fulfilling its primary mandate to protect civilians, noting that tens of thousands have sought refuge inside U.N. peacekeeping bases.

“We’ve stepped up to the plate and done the very best we could,” he added.

African peacekeeping troops not under the U.N. banner often have even less equipment, training and resources. Yet, they are increasingly being called upon to help contain crises around the continent.

In northern Mali, an African force comprised of soldiers from neighboring countries deployed too late to prevent Islamist radicals — including Al Qaeda’s West and North African affiliate — from carrying out widespread atrocities against civilians.

In the Central African Republic, African Union peacekeepers have been unable to stop the brutalities committed by Muslim Seleka rebels and Christian militias in the sectarian conflict. Soldiers from Chad, a Muslim nation that is part of the peacekeeping force, have been accused of supporting the Muslim rebels.

“Even with increased engagement in peace operations, questions remain about the quality and capability of African troops,” Comfort Ero, the Africa director for the International Crisis Group, wrote in a blog on the group’s Web site last month.

In both Mali and the Central African Republic, or CAR, hundreds of soldiers from France, the former colonial power, were sent to defuse the crisis after African peacekeeping forces failed to do so.

Still, when resources, training and a strong mandate are provided to African peacekeepers, there have been some successes. The African force in Somalia, led by Uganda and Burundi and backed by the United States and its allies, is credited with driving out the al Qaeda-linked al-Shabab militia from major cities, though Somalia remains far from stable.

In the Democratic Republic of Congo, where the U.N. mission has been widely criticized as unable to protect civilians, the recent deployment of a rapid reaction U.N. combat brigade with a strong mandate helped defeat the M23 rebels.

The crisis in South Sudan, though, threatens to weaken other peacekeeping missions in Africa. Last month’s U.N. resolution allows troops from other trouble spots such as Sudan, Liberia, Ivory Coast and Congo to be temporarily redeployed to bolster the U.N. mission in South Sudan.

Even with thousands of peacekeepers, a key reason for the strife in South Sudan is a refusal by the United States, European and African powers who played a key role in creating the independent nation to acknowledge its political divides. For more than a year, there were clear signs of a deep split within the ruling party, pitting President Salva Kiir against his former vice president, Riek Machar.

Now, both men’s loyalists within the army threaten to propel the country into civil war.

“In South Sudan, there could have been a bigger international diplomatic push to address the deepening schism within South Sudan’s ruling party when it began to implode in the summer,” said Prendergast. “A U.N. mission alone cannot usually address these scenarios, so the countries with leverage need to show up in a major way and work to prevent potential conflagration. This didn’t happen in South Sudan, and the result is obvious.”