POLITICIANS often promise more than they deliver, but those in Nigeria bit off more than most when they campaigned on a pledge to “defeat Boko Haram”. Six weeks after the inauguration of its new president, Muhammadu Buhari, the government must be wishing it had promised something less ambitious. Boko Haram seemed to be on the ropes a few months ago. Despite its threats to disrupt the election at the end of March, the vote was largely peaceful, and the militants had been pushed back from many of the towns they had captured. Yet in recent weeks the group has struck back from its remote redoubts, killing more than 200 people in the week to July 5th (and more since then) in a series of attacks across the north.

Bombs were detonated in the major cities of Jos and Kano, neither of which had been attacked since February. Boko Haram also showed that it can still operate across borders: two suicide bombers struck Chad’s hitherto unscathed capital, N’Djamena, in mid-June, blowing themselves up outside police headquarters, killing 34 people. Horseback and motorbike-mounted raiders attacked another neighbour, Niger, twice in two weeks.

The recent attacks suggest that since their ejection from urban areas, Boko Haram jihadis have regrouped in the forests and mountains along the border with Cameroon, or have melted into local populations disguised as merchants or beggars. Many of its 6,000 fighters are still active and its leadership is intact. The group may lack the sophistication to administer territory, but it has been honing its skill at hit-and-run attacks since 2009.

Nigeria’s army, by contrast, is finding counter-insurgency far more difficult than merely liberating captured towns. It has also lost much of the support that contributed to its victories earlier this year. Mercenaries who helped turn the tide in the north-east have been sent home and Chadian soldiers have pulled back over the border. Morale among poorly equipped Nigerian troops is plummeting again. “[It is becoming] the way it used to be before—[when] one man [was issued with just] one bullet [per target]—it’s just the same now,” says one military man.