As the United Nations’ Force Intervention Brigade turns it focus on the Democratic Forces for the Liberation of Rwanda, it knows all too well that success against the FDLR is unlikely to come as quickly and swiftly as that against the M23 rebels.

The Brigade, which is made up of troops from Tanzania, South Africa and Malawi, opened its campaign against the FDLR on November 27.

Yet nearly three weeks later, it has done little besides reopening a road connecting parts of North Kivu to Goma, the provincial capital, which the UN says the rebel group has controlled for years.

This contrasts starkly with the offensive against M23, which was swift, daring in approach and unrelenting in execution. This combination saw the Brigade roll back the rebels from the vast territory they had occupied for over a year in a fraction of the time most observers had predicted it would take them.

The seemingly slow progress against FDLR is explained in part by the asymmetrical way in which they organise themselves as well as their unconventional military tactics, noted a security analyst familiar with the group.

For instance, it has embedded itself among the civilian population, making any offensive against it more difficult, Martin Kobler, the Special Representative of the UN Secretary-General in the DR Congo, told the UN Security Council on December 11.

In spite of Rwanda whittling down its military and numerical strength, which the UN currently estimates at between 1,500 and 1,800 combatants, the group has maintained a coherent political and military structure compared with M23, which appeared disjointed throughout its 20-month span.

Security analysts in Rwanda say it is through this network that the two-decade-old group still propagates the hate ideology that fuelled the 1994 genocide in which up to a million Rwandans, mostly Tutsi, died.

They add that such hatred poses both a physical and ideological threat not only to the country but the region, given how spread out the group’s targets are.

“One of the difficulties will be the grey zone between FDLR combatants, the Rwandan Hutu civilians on Congolese soil, and the Congolese Hutu. There is a high risk of collateral damage, to use the ugliest word on earth,” Kris Berwouts, who consults on conflict, security and democracy in Central Africa, said.

Indeed, the FDLR has hinted at a scenario like that. In a December 6 warning to the UN and the international community, the group stated that any attack against it would not be limited to its members only but would affect Congolese civilians and Rwandan refugees.

This is the sort of risk likely to weigh heavily on decisions about how the Brigade should engage the FDLR. Yet should it hesitate too long, it risks being accused of being partial.

Rwanda expects the FDLR to be eliminated in much the same way as the M23. President Paul Kagame said as much to Russell Feingold, the US Special Envoy for the Great Lakes Region and the Democratic Republic of the Congo, when the latter visited him on December 4.

The two leaders “agreed that a sustainable solution [to peace and stability in the region] must include the neutralisation of the FDLR as a matter of priority,” read a statement from Kagame’s office.

If that were not difficult enough, there is the matter of the group’s long-running collaboration with the Congolese national army, which, essentially, is supposed to lead the attacks against it.

According to a June report by the UN Group of Experts on the DR Congo, the FARDC enhanced alliances with FDLR when M23 rebels overran Goma in November last year.

“In January this year, two former FDLR soldiers witnessed separately meetings between FARDC and FDLR in the Tongo area, during which they exchanged operational information,” the report says.

“Between January and April 2013, a former FDLR soldier witnessed four distinct ammunition transfers by the FARDC based at Bambo to FDLR, while in February, another former FDLR soldier saw FARDC hand over ammunition to the FDLR, also at Bambo,” it adds.