The UK and other Western powers failed to spot the warning signs of instability in Mali and the Central African Republic until it was too late, MPs have said as they urged the Government to step up efforts to engage with problems in the region.
The Foreign Affairs Committee criticised the "scant resources" allocated to the Western Sahel-Sahara and said there had been a "costly error" in failing to anticipate the effects of the collapse of Muammar Gaddafi's regime in Libya on its neighbouring countries.
The report warned there were "significant gaps" in information about terrorist groups operating in the region and said improving the quality of intelligence should be a priority for the UK and its allies.
The MPs said: " A new front line of violent extremism has opened up in the Western Sahel-Sahara region of Africa.
"Jihadists have put down roots in remote or marginalised areas, taking advantage of weak or non-existent state and security institutions, lucrative local criminal networks, and public disillusionment and anger with the corruption and mis-governance of political elites.
"In Libya, Mali and Nigeria the threat is currently greatest, but all countries in the region are at risk. Concerted international co-operation is required to address this threat: there need to be robust security responses, but also large-scale political and economic interventions to address the underlying causes of instability."
The UK Government has set out a "bold vision" to increase its political, security and economic engagement with the region.
But the MPs said the "mismatch between the Government's ambitions and its scant diplomatic resources in the region is vast and irreconcilable.
"The Government should consider enhancing its diplomatic presence in the Western Sahel and the Maghreb, within the tight financial constraints that the FCO (Foreign and Commonwealth office) is currently forced to operate in.
"It should also avoid inflated rhetoric and be realistic in its aims, focussing on what the UK does best. "
The MPs said the West seemed to turn a blind eye to events in Mail "failing to spot the warning signs until it was too late" and the pattern was repeated in the Central African Republic.
"The UK and its allies need to examine their early warning systems for the region," the committee said.
"There was also a failure by the UK Government to anticipate the full effects of the Gaddafi regime's collapse on its Saharan neighbours, and therefore to try to mitigate them. This has been a costly error."
The report said it was "s omewhat troubling to acknowledge" that " there are some significant gaps in information" about the region, particularly in relation to the terrorist groups operating there.
"We still know little about the insurgency's leaders: in some cases we do not know for certain if they are living or dead.
"We know relatively little about how groups are organised, how strong or well-armed they are; what their income is, and who their external supporters are.
"We do know that they t end to thrive on the remote peripheries of the region, which makes them hard to monitor and track, and we have learned that gathering evidence about the groups by infiltrating them is very difficult.
"The Government has itself acknowledged that it is still learning about the region's complex dynamics and that there are gaps in its knowledge."
Committee chairman Sir Richard Ottaway said: "Overall, our committee has uncovered a worrying pattern of unsightedness on the part of the UK and others in relation to events in and around the Western Sahel region.
"A common thread appears to be a weakness of analysis in relation to crises that straddle both North and West Africa. The Sahara may be a departmental barrier within the Foreign Office but it is not one for terrorists.
"The UK's diplomatic presence in the whole area is extremely small relative to other parts of the world.
"We would urge the UK Government to look at expanding its presence and depth of knowledge in relation to the whole region, in view of the foreign policy challenges that lie ahead."