The Boko Haram conflict has finally gone regional. While the Nigerian military has launched what witnesses call its most determined assault on the insurgents in years, Nigeria’s neighbors—Niger, Chad, and Cameroon—have entered the war in earnest, engaging Boko Haram on their own territory and across the border on Nigerian soil.

On Feb. 4, troops from Chad crossed through Cameroon into Nigeria, retaking a strategic border city called Gambaru. Boko Haram retaliated in Fotokol, across the river in Cameroon, massacring hundreds. Cameroon has now retaken that city, too, and deployed Israeli-trained elite forces across 250 miles of border frontline.

Pushing ahead, the Chadians expelled Boko Haram last week from Dikwa, a Nigerian town only one hour’s drive from Maiduguri, the capital of Nigeria’s Borno State and a metropolis of 2 million. On Saturday, a separate Chadian column arrived in Diffa, Niger, a city whose population of 60,000 swelled threefold last year with the influx of Nigerian refugees. From there, Chad and Niger, which launched its own raids on Nigerian soil for the first time last week against two suspected guerrilla hideouts, are preparing to deploy joint patrols.

Boko Haram’s heartland—Nigeria’s Borno, Yobe and Adamawa states—borders Niger and Cameroon and is separated from Chad only by the rapidly drying Lake Chad. Porous frontiers were an advantage for the insurgents, who could shelter from Nigeria’s army, hide in savanna or low mountain terrain, and melt into the local population. Until last year, the group rarely attacked targets in neighboring countries, while the armies of those countries did little to root out Boko Haram’s rear bases.

That pattern has changed, in a regionalization of the Boko Haram war that marks a clear turning point. It opens new prospects for defeating the group, but creates new risks. In March, a new 8,700-strong force of troops from Nigeria, Chad, Cameroon, Niger, and Benin is slated to launch an offensive that commanders hope will be decisive. The United States and France are playing a crucial role, supplying intelligence, training, and logistics.

But Boko Haram is retaliating on multiple fronts too, with two attacks on Diffa and its first raid on a Chadian village. As fears grow of an entente between Boko Haram and other jihadis, including the self-styled Islamic State, stoked by ominous new videos that echo ISIS productions, the current campaign must deliver fast, or risk backfiring dangerously.

In the core conflict zone of northeast Nigeria, the escalation has raised hopes. Alkasim Abdulkadir, a Nigerian journalist just back from Yola, capital of Adamawa state, said the sky there was streaked every few minutes by fighter jets taking off from the air force base. The Nigerian army has said it retook several towns in recent days, although there is no independent confirmation, and Boko Haram still commits attacks daily. But Abdulkadir said displaced people in Yola were starting to travel back to their villages to take stock of the situation. The current offensive feels unprecedented, he said: “One man told me, ‘If they had fought this way from the beginning, we wouldn’t be where we are now.’”

Indeed, the conflict’s regional turn reflects the failure of Nigeria’s military to end an insurgency that has raged for six years. International pressure ramped up in May 2014, when France hosted a summit of Nigeria and its neighbors, with the U.S. and other partners present. A month earlier, the mass abduction of the “Chibok girls”—just one in a litany of Boko Haram horrors—had raised the conflict’s visibility. The 219 still-missing young women of Chibok remain a spectral presence that shadows the conflict.

No one knows the fate of these women; indeed, no one knows much that is certain about Boko Haram at all. The fog of war that has enveloped this conflict is extraordinary for modern times. Close news coverage is scant, due partly to the danger of reporting in the conflict zone and partly to the under-resourcing of local media outlets. A cottage industry of outside analysts has sprung up, valiantly chasing down intelligence but mostly reading the tea leaves. The unknowns are so fundamental that they hamper the development of counter-insurgency tactics, let alone informed pressure by the Nigerian or global public.

For one thing, even though Boko Haram’s shift from millenarian movement to armed insurgency is understood (it happened in 2009, after its founder, Mohammed Yusuf, died in police custody), the movement’s current structure is unknown. Its leader, Abubakar Shekau, is said to have look-alikes, so that each video of his rants that the group releases prompts serious debate about “which Shekau” it shows. Indeed, there may be multiple branches of Boko Haram, operating in a decentralized or uncoordinated manner. Ties between Boko Haram, al Qaeda in the Islamic Maghreb (AQIM), and ISIS, among others, are also rumored, but have yet to find definitive substantiation.

Boko Haram’s ties with politicians in Nigeria and outside also draw intense speculation. Such ties surely exist—in its pre-insurgent incarnation, based in Maiduguri, the group was one of many social forces active in Borno state politics—but no one knows their current state. One theory holds that Chad’s president, Idris Deby, provided covert support to the group until recently, when it spun out of control. It is apparent that Boko Haram’s supply of vehicles and weapons comes largely across the Sahara, suggesting some complicity or complacency in Niger and Chad, but it is not clear at what level.

This uncertainty poisons any effort to end the war. Broadside accusations of ties with Boko Haram fly freely in Nigerian politics. Boko Haram’s access to armored vehicles raises the question of how they were captured or bought. Every war produces profiteers who have an interest in its continuation; who they are—beyond fuel smugglers and other local opportunists—is this war’s greatest mystery.

As a result, the now-allied armies still look at one another askance. Tempers have flared: After a Niger official supposedly said that Niger’s troops, unlike Nigeria’s, “don’t run away,” Nigeria’s army spokesman, Gen. Chris Olukolade, delivered a rant on Twitter against “others reputed for looting” and “collaborating with terrorists.” Even Nigeria’s permission for Chad to enter its territory, on one level an unprecedented act of cooperation, has raised fears that the Chadians might not leave.

Stitching together a regional push against Boko Haram is a hard task, but it is crucial for ending the conflict. One advantage of regionalization is that it offers a clearer role for the French and American military apparatus that embraces Nigeria’s neighbors. France has a major presence in N’Djamena, Chad’s capital, which is only 75 miles from Nigeria. It is headquarters to Operation Barkhane, the French security umbrella that spans the entire Sahel region, as well as the site of a new coordination cell that France has set up for the countries fighting Boko Haram.

Reached in N’Djamena, a French officer emphasized that Barkhane’s mission does not permit operations in Nigeria, though it does encompass support for Niger and Chad to defend their territory. The separate Boko Haram coordination cell includes 10 dedicated French staff and partners from Chad, Niger and Cameroon. France also provides direct support to these countries that can include fuel and ammunition. The officer said that Nigeria has not yet said whether it would join the cell.

The United States, meanwhile, has Special Forces and drones based in Niger. An annual U.S.-led exercise, Operation Flintlock, is now taking place in Chad and includes, among others, the nations involved in the Boko Haram conflict. Asked for comment, a U.S. Africa Command spokesman said: “We are providing funding and assistance to Nigeria and its neighbors—Niger, Cameroon and Chad—to train military personnel in border security, command and control, and other best practices to counter violent extremism.”

On Saturday, when Niger’s president, Mahamadou Issoufou, visited Diffa, he met not only his own forces and the Chadians who had just arrived, but also French, American, and Canadian soldiers stationed there. As regional war ramps up, so will Western involvement, although in background roles.

In the near term, the biggest uncertainty the campaign faces may not be military. Instead, it is Nigeria’s presidential election, which was due Feb. 14 but postponed to March 28, ostensibly on security grounds. President Goodluck Jonathan, who is running for re-election, has promised sufficient security improvement in the northeast to make holding the election possible. Supporters of opposition candidate Muhammadu Buhari, a former military ruler, argue that the election was moved to buy the president’s party more time; many suspect the president and military establishment of seeking to retain power at any cost.

The worst outcome for the campaign against Boko Haram would be a canceled or botched election, or any scenario that failed to produce a clear winner. Should Nigeria fail to hold its elections or descend into post-election political paralysis or violence, many innocent victims will suffer—but none more so than the population of Borno, Yobe and Adamawa states and the border regions of Nigeria’s neighbors.