Pakistani and U.S. intelligence forces last week captured the Afghan Taliban’s top military commander, dealing a major blow to the insurgent group and marking a potential turning point in the Afghanistan war. Mullah Abdul Ghani Baradar is the highest-ranking Afghan Taliban figure to be apprehended since the war began, in 2001. Baradar had been directing the Taliban’s day-to-day operations from the Pakistani port city of Karachi and was seen as a likely successor to ailing Taliban founder Mullah Mohammad Omar.

The arrest marks a new level of cooperation between the U.S. and Pakistan’s Inter-Services Intelligence agency, which historically has tolerated the Taliban’s presence in Pakistan and supported the group’s operations in Afghanistan. The ISI and the CIA were reportedly jointly interrogating Baradar, but authorities were not commenting about whether he was cooperating.

Baradar’s capture represents a significant “change of course” in Pakistan’s relationship with both the Taliban and the U.S., said Steve Coll in After years of promoting Taliban guerrilla violence in Afghanistan, Pakistan has shifted toward negotiations. Baradar’s arrest can be seen as a warning: The more the militants “refuse to lash themselves to Pakistani political strategy, the more vulnerable they become to a knock on the door in the night.”

While Baradar’s capture certainly seems like good news, said Colin Cookman in, it “may rebound in unpredictable ways.” Without their chief military strategist, the Taliban’s “capacity for coordinated violence” has been diminished. But the Taliban’s leadership could now fragment, complicating negotiations toward a political settlement in Afghanistan.

The Taliban hardly seem ready to lay down their arms, said Tom Coghlan in the London Times. They have lost high-ranking leaders before and kept on fighting. Moreover, we can’t rule out the possibility that Baradar was caught precisely because he had been showing “too much interest in negotiation with the West,” so was betrayed by militant Pakistani operatives who oppose that course. “Things are rarely what they appear in this region.”