The latest in a series of military coups in West Africa has led to fears of broader regional conflict, with a major political bloc in the region threatening military intervention in Niger unless the elected government is restored.

The Economic Community of West African States (ECOWAS) said Friday that it was prepared for military action and that it had decided on a "D-Day" for intervention in Niger, where a junta led by Niger's presidential guard detained President Mohamed Bazoum on July 26.

Efforts at mediation have so far failed, with Niger missing an ECOWAS-installed deadline of restoring Bazoum to office within a week and the bloc rejecting a junta proposal to return to democracy in three years.

"All we are saying is that we are not going to engage in endless dialogue," said Abdel-Fatau Musah, ECOWAS's commissioner for political affairs, peace and security. "It must be fruitful, and its objective must be the restoration of constitutional order" as quickly as possible.

The situation is complicated by the fact that three other members of the 15-member ECOWAS are suspended as they have had their own military coups in recent years. These countries — Mali, Burkina Faso and Guinea, all former French colonies in the Sahel — have indicated they may side with Niger's military government in the case of a war.

The situation is a major test of the political will and organizational capability of ECOWAS, one of the most important organizations in Africa. It comes as major Western powers like France and the United States have stepped back from the region, while the Russian mercenary Wagner Group has allied with some military governments.

What is ECOWAS?

ECOWAS was founded with the Treaty of Lagos in 1975. Initially designed as a way to grow economic and monetary ties, it has expanded its scope significantly to include security work and military coordination.

In 1990, it formed a peacekeeping alliance, the Economic Community of West African States Monitoring Group (ECOMOG), beginning a tradition of armed involvement in member states' problems.

Overall, ECOWAS membership has remained relatively static over the years. Of its 15 current members, all but one were part of the founding group of nations (the small island nation of Cape Verde joined in 1977). Only one country, Mauritania, has left the organization.

However, a spate of coups over recent years has led to deep divisions in the bloc. Mali and Guinea both saw coups in 2021, as did neighboring Chad and Sudan, both non-ECOWAS members. Burkina Faso's military took over that country in 2022.

Nigerian President Bola Ahmed Tinubu seemed to acknowledge the problem in July, before the Niger coup, when he said he was drawing a line in the sand on military takeovers. "We will not allow coup after coup," Tinubu said as he assumed the position of ECOWAS chair.

Has ECOWAS intervened before?

The last time ECOWAS intervened militarily in a member state was in 2017, when it sent forces to Gambia.

There, 7,000 soldiers were sent from Ghana, Nigeria and Senegal to force the transfer of power from longtime president Yahya Jammeh, who contested the results, to Adama Barrow, the democratically elected leader. Jammeh eventually conceded without the need for violence.

Before that, troops linked to the West African bloc had served as a peacekeeping force in Liberia and Sierra Leone during the 1990s.

But ECOWAS has been criticized for inconsistency in interventions. Though it stepped in in Gambia in 2017, it did not militarily intervene later when Mali, Guinea and Burkina Faso saw coups. Instead, it responded by suspending memberships and placing sanctions on the military governments.

"These inconsistencies have damaged ECOWAS's legitimacy, giving the military juntas less reason to take the organization seriously," Kamissa Camara, a former Malian foreign minister, said in a recent interview with the Danish Institute for International Studies.

How militarily strong would an ECOWAS force be?

Musah, the commissioner for political affairs, peace and security, said Friday that all non-suspended members of ECOWAS had said they would contribute to the military intervention in Niger, with the exception of Cape Verde, which does not have a formal military.

In sheer numbers, it could be a powerful force. Nigeria, the most populous country in the bloc, is also the most militarily capable with an estimated 223,000 soldiers and a military budget of over $3 billion in 2022, the third-highest in all of Africa, after Algeria and Egypt.

In terms of personnel and budget alone, the ECOWAS bloc would dominate the far smaller Niger military — even if the military governments of Mali and Burkina Faso were to support Niger's military, as they have indicated they might. The landlocked Niger also has significant logistical weaknesses: Its electricity is supplied by Nigeria, for one.

But weaker forces have routed stronger forces throughout history. An intervention in Niger would likely require a far more substantial force than the 5,000 ECOWAS soldiers seen six years ago in Gambia, a far smaller country in both physical size and population.

Many ECOWAS countries, including Nigeria, are struggling under their own security problems that may make it hard to send soldiers and equipment to Niger.

Reuters in the capital city of Niamey reported last weekend that Niger's junta has seen a rush of volunteers seeking to defend the country against any invading force. Niger's junta has also threatened to kill the detained President Bazoum if there is a military intervention, according to the Associated Press.

Is military action by ECOWAS widely supported?

In its statements, the African Union has avoided discussion of military intervention. The 55-nation bloc appears to be divided on the issue, raising questions about the legality of an ECOWAS intervention without African Union approval.

Some countries, like Niger's neighbor Algeria, have expressed concern about whether the conflict could have unintended consequences. "You can start a military intervention, but you never know how it will end," Algerian Foreign Minister Ahmed Attaf said during a recent visit to Washington.

The U.S. government has said it supports ECOWAS, but emphasized it favors diplomacy over military intervention. There are roughly 1,000 U.S. troops in Niger, where they had been working on an anti-terrorism mission, and a conflict in the country could place those servicemembers at risk of conflict.

U.S. officials have continued to visit Niger, although incoming Ambassador Kathleen FitzGibbon did not formally present her credentials when she visited Niamey this past weekend.

France, which still has about 1,500 of its own troops in Niger, was asked to intervene by the ousted government but declined, according to accounts from former officials. The French government has lent its support to an ECOWAS action, but it faces a wave of anti-French sentiment across the Sahel.

Russia, meanwhile, has warned against military action, suggesting it would lead to "sharp destabilization" in the wider Sahel region. Some accounts suggest Niger's junta has sought aid from Wagner, the Kremlin-linked Russian mercenary group which operated in Mali.