While West African leaders still hold hope that a solution to the Malian crisis can be reached through peace talks, a military operation is also being prepared in case force is required to oust the Islamist militants from the north of Mali.

The Economic Community of West African States (Ecowas) wants to send 3,300 soldiers. Whether that number can be reached is not clear.

Nigerians have formed the backbone of previous military operations in the region - sending 10,000 soldiers to Sierra Leone in the 1990s.

But on this occasion less than a battalion will be sent - probably about 700 soldiers.

Fighting well-armed Islamist jihadis, who are allegedly swelling ranks with local recruitment as well as the arrival of foreign fighters, in harsh desert conditions is a very different proposition to defending Monrovia or Freetown Charles Hunt, Security lecturer

"We are encouraging the Malians to do as much as possible for themselves because the issue of sovereignty is a very sensitive thing," Admiral Ola Ibrahim, Nigeria's chief of defence staff, told the BBC.

Oil-rich Nigeria is the powerhouse in the region. By paying two-thirds of the Ecowas annual budget, it earns the right to have its voice heard at a hefty volume.

But this time Nigerian soldiers - along with troops from Niger, Burkina Faso and elsewhere in the region - are set to play a support role, with the Malian army taking the lead.

Ecowas officials say 13 out of its 15 members have pledged to contribute troops, but the numbers they will send are not clear yet.

"We are talking about a sovereign state here where the pride of the army itself is also on the line.

"We will encourage and support them to whatever extent to liberate their country," said the head of Nigeria's military, clearly aware that Mali does not want its nose put out of joint.

'Split and demoralised'

He did however say that it was still likely that Nigerian soldiers would become engaged in the fighting in northern Mali.

This would not be surprising given the poor state of the Malian army, which abandoned the north without a fight in April.

"The Malian army is split, demoralised and doesn't have the experience and coherence in terms of structure and hierarchy to be able to partner any international force," says Kwesi Aning of the Kofi Annan International Peacekeeping Training Centre in the Ghanaian capital Accra.

Image caption Nigerian soldiers have taken part in peacekeeping forces in other parts of Africa

For about eight years, efforts have been made to establish an effective Ecowas Standby Brigade as part of the AU's African Standby Force. Nigeria ought to be able to play a key role because of its experience.

"Nigeria has accumulated plenty of UN peacekeeping experience and therefore has more trained and suitable personnel to send than in the 1990s," says Charles Hunt, a former consultant to Ecowas on the development of its standby force.

Nigerian soldiers have been on peacekeeping duty in countries like Lebanon and the Sudanese region of Darfur.

They also intervened in Chad's civil war in the 1980s alongside troops from Senegal and Zaire.

But a mission to northern Mali would provide very different challenges compared with previous interventions in West Africa including Liberia and Sierra Leone.

"Fighting well-armed Islamist jihadis, who are allegedly swelling ranks with local recruitment as well as the arrival of foreign fighters, in harsh desert conditions is a very different proposition to defending Monrovia or Freetown," says Mr Hunt, a lecturer in international security at the University of Queensland.

"It is also very different from monitoring the ceasefire line between north and south Cote d'Ivoire [Ivory Coast]."

'Heavy-handed' tactics

The Nigerian force in Sierra Leone in the late 1990s, known as Ecomog, faced a daunting challenge: Preventing marauding, brutal rebels from seizing power in a broken country.

Major Ecowas interventions 1990: Sends up to 12,000 troops to intervene in Liberia's civil war

1997: Deploys large-scale force in Sierra Leone after rebel coup

1999: Peacekeepers sent to Guinea-Bissau after conflict between president and military chief

1999: Recaptures Freetown in Sierra Leone

2003: Peacekeepers deploy to Liberia to oversee peace accord as President Charles Taylor goes into exile

2012: 600 troops sent to Guinea-Bissau to oversee transition to civilian rule following a coup

They played a major role in pulling Sierra Leone back from the brink, although the tactics were often heavy-handed and included summary executions.

The same accusations are being made today as the Nigerian military fights the Islamist militant group popularly known as Boko Haram in the north of the country.

Amnesty International says people are caught between the military and the Islamists.

An Amnesty report entitled Nigeria: Trapped In The Cycle Of Violence says the army's tactics are even boosting support for Boko Haram.

The Nigerian military rejected the report as subjective, said allegations of indiscipline were being investigated and maintained the troops were doing a good job in difficult conditions.

"The enemy is not well defined - they are your citizens, some of them. And they come around deploying an unusual approach - like suicide bombings which are alien to this country, bombing churches or mosques and killing people randomly," said Adm Ibrahim.

"The armed forces of the Federal Republic of Nigeria can beat its chest. We are professional. We seek to draw on the best practices," he added.

'No cakewalk'

If all of us are united to neutralise this embarrassing situation in northern Mali, it will come with its costs, but it will be worth it Admiral Ola Ibrahim, Nigeria's chief of defence staff

Should Nigerian forces end up in northern Mali, they will face the same challenge of engaging an often hidden enemy without causing severe suffering for the local population.

An Ecowas mission to Mali would also throw up huge logistical challenges:

It is 1200km (745 miles) by road from the capital Bamako to the Islamist held city of Gao

The availability of air transport including helicopters is not yet known

The onset of the harmattan season - a dry and dusty wind which blows south off the Sahara Desert - meaning visibility is likely to be poor until March.

"We have never underestimated the challenge," says Adm Ibrahim, who describes those in control of northern Mali as an embarrassment as well as a threat to the international community.

"We learnt that they had an enormous supply of arms from Libya in North Africa. It is likely that they will expose themselves to combat to suit them in the terrain they occupy," he told the BBC.

With insecurity in northern Nigeria and parts of the centre of the country, as well as concern over the volatile Niger Delta, it is not surprising that some observers question whether Nigeria can afford to send any soldiers abroad right now.

Image caption The Islamists have business relationships with quite a number of the criminal gangs in West Africa

"There is a view that the Nigerian army has engaged in the most serious deployment of troops in Nigeria since the civil war. But I still believe they have the capacity to deploy in Mali," says international relations analyst Aderemi Oyewumi.

"In my view though it is not going to be a cakewalk. My biggest fear is that could attract fellow Islamists from elsewhere as we saw in places like Iraq or Afghanistan," says Abuja-based Mr Aderemi.

If there is a military fight, the Islamists' rallying call would be given extra impetus by the fact that the United States, France and other European countries are offering support to the Ecowas mission - in every way possible except boots on the ground.

Domestic calculations

The ancient trade routes between the Mediterranean and sub-Saharan Africa pass through a wide belt of semi desert land known as the Sahel. Home to the Tuareg people, it has become a largely lawless area where weapon smuggling is rife - ideal terrain for the Islamist militants to try to establish a safe haven.

"There are opportunistic relationships between the jihadis, the Tuaregs and the traffickers - narcotics smugglers and human-trafficking gangs," says Mr Aning.

"We've seen the way al-Qaeda opportunistically uses a jihadist rhetoric but it has a hard-nosed business relationship with quite a number of the criminal gangs that we see in West Africa."

This is clearly no longer a Malian problem but a West African one, and that is why Ecowas is preparing to act and wants other nations involved.

Algeria, which shares a 1,400km border with northern Mali, has been reluctant to back the military approach.

It fears Islamists could move across the porous border and potentially reignite an Islamist insurgency at home - one which killed tens of thousands in the 1990s.

The prospect of the Islamist militants in Mali linking up with Boko Haram is also a worrying prospect for Nigeria. Nigeria's military chief hopes Algeria as well as Mauritania can still be persuaded to help out.

"Algeria may have done a lot of calculations and seen that the effect of intervention would be telling on their own peace and security," says Adm Ibrahim.

"But if all of us are united to neutralise this embarrassing situation in northern Mali, it will come with its costs, but it will be worth it because it is a threat to our peace and security."