By Michael Kugelman, Special to CNN

Editor’s note: Michael Kugelman is the senior program associate for South Asia at the Woodrow Wilson International Center for Scholars. The views expressed are his own.

On August 5, 2009, a U.S. drone strike killed Pakistani Taliban (TTP) leader Baitullah Mehsud. In the days that followed, his death was confirmed by the TTP, which immediately made plans to select his successor. One person, however, had a different view on what happened – an energetic young TTP commander named Hakimullah Mehsud. He’s just “a bit sick,” he told a reporter.

What a strange remark. And yet four years later, the unhappy response in Pakistan to the death-by-drone of Hakimullah, Baitullah’s successor, is similarly perplexing.

Hakimullah Mehsud enjoyed, even by the TTP’s savage standards, an outsize reputation for cruelty. He contrasted sharply with Baitullah Mehsud, to whom he served as a close aide. Baitullah was portly and afflicted by diabetes – a condition that caused him chronic leg pain. He was killed while reportedly reclining on the roof of his father-in-law’s home, receiving a leg massage from a female companion. Hakimullah, by contrast, was big and athletic – and is believed to have survived several prior strikes.

Not surprisingly, the TTP, always an uncompromisingly brutal organization, became even more violent with Hakimullah Mehsud at the helm. The group spared no one – from polio vaccination workers and religious minorities to kids playing soccer.

Such were the depths of Mehsud’s brutality that late last year, according to Reuters, TTP officials were clamoring to replace him with his more moderate deputy, Wali-ur-Rehman. However, a drone strike killed ur-Rehman in May – just after Mehsud had overseen a brutally efficient campaign of violence against three major Pakistani political parties in the lead-up to national elections.

More from GPS: Time for U.S. to end drone secrecy

Fast forward to the last several days. Many Pakistanis, particularly conservative opposition politicians and talks show hosts, but also the Foreign Ministry and the general public, have reacted to the death of Mehsud with sadness and anger. Aside from comments made by liberal Pakistanis on social media, few Pakistanis have publicly celebrated Mehsud’s passing.

Why such unhappiness about the death of a notorious mass murderer? One reason is Pakistan’s reflexive anti-Americanism, rooted in a deeply held perception that Washington, through drone strikes and other measures, endlessly meddles in and messes in Pakistani affairs. Many Pakistanis (with some reason) believe that the U.S. pursues policies in Pakistan with blatant disregard for the damaging consequences, which are invariably borne by Pakistanis.

According to this narrative, polio inoculation efforts have suffered in Pakistan ever since Shakeel Afridi, a Pakistani doctor cooperating with the CIA, helped track down Osama bin Laden by using a fake polio vaccination campaign. Now, the argument goes, a campaign of reprisal attacks against Pakistani civilians will surely follow Mehsud’s death.

To be sure, most Pakistanis are unhappy not because Mehsud was killed, but because of how and when he was killed. Some are bitter that Pakistan’s vaunted military couldn’t “drone” Mehsud itself, or eliminate him through a ground offensive. The first option has always been a non-starter, given Washington’s unwillingness to share sensitive technology with its mistrusted ally. As for the second option, Pakistan’s army has waged anti-TTP offensives for years. However, it hasn’t entered North Waziristan, where Mehsud was located, because it’s a sanctuary for militant organizations that serve as proxies for Pakistan’s security establishment.

More from GPS: What Pakistan thinks

Islamabad says it’s angry because the United States “sabotaged” prospective peace talks with the TTP (hours before Mehsud’s death, Islamabad said it had launched a dialogue process). The drone strike, according to Pakistan’s interior minister, “murdered the hope and progress” for peace. The Pakistani government – and many voters who brought it to power in May – claims that negotiations provide the only path for ending the Taliban bloodshed convulsing the country, and that Washington has obliterated this only path.

So, with Islamabad vowing to “review all perspectives of the relationship with the U.S,” and with the political leadership of Khyber-Pahktunkhwa Province voting Monday to block NATO supply routes later this month if drone strikes continue, Mehsud’s death has seemingly sparked a fresh crisis in U.S.-Pakistan relations.

Or has it? Eliminating Mehsud arguably constituted a rare shared interest for the two reluctant allies. The TTP vows to destroy the Pakistani state, and has staged numerous brazen assaults on Pakistani military facilities – including the general headquarters building (Pakistan’s Pentagon) in October 2009, just weeks after Mehsud took over. It has claimed thousands of Pakistani military lives – including a former intelligence official and, just weeks ago, the top general in the Swat Valley.

But Mehsud was not an exclusively Pakistan-centric jihadist. He helped mastermind an attack on a CIA base in Afghanistan, and his organization reportedly trained the Pakistani-American who attempted to blow up Times Square. Hours after that unsuccessful attempt, the TTP released a video in which Mehsud issued a chilling threat: “The time is very near when our fidaeen will attack the American states in their major cities.” After Mehsud’s death, Rep. Mike Rogers, who chairs the House Intelligence Committee, suggested that Mehsud posed an imminent threat to U.S. soldiers in Afghanistan. “There was some information recently that concerned us about the safety of our troops,” he said on CBS’ “Face the Nation.”

It’s quite possible Washington informed the Pakistani security establishment about the strike in advance. And it’s equally possible that the Pakistani military, as it has on numerous other occasions, gave its blessing. This would shed further light on Islamabad’s anger: Not only is it indignant that Washington sent its peace plans up in flames, but it’s also furious that the Americans were conspiring with the Pakistani security establishment behind the government’s back.

Or, then again, maybe not. When it comes to U.S.-Pakistan relations, what Pakistani officials say in public often differs from what they say in private. The angry denunciations of recent days may be no more than a sop to a rabidly anti-American Pakistani public. Behind closed doors, government officials may well be cheering the decision to drone Mehsud.

Either way, the coming days could be bloody. A TTP spokesman has vowed that “every drop of Hakimullah’s blood will turn into a suicide bomber.”

But this tough talk obscures an important fact: Despite its ferociousness, the TTP has been weakened significantly in recent years by Pakistani military assaults and U.S. drone strikes – and Mehsud’s death is the biggest blow yet.

The TTP declared this weekend that it has ruled out talks with the government. However, its increasing vulnerabilities and fissures (inter-commander dissension has complicated efforts to appoint Mehsud’s successor) may, in time, convince it to change course. It may also favor talks out of fear that the Pakistani Army might eventually capitalize on the TTP’s unsettled state and launch a fresh offensive. That fear isn’t misplaced; Gen. Haroon Aslam, a frontrunner to become Pakistan’s next army chief later this month, led a successful offensive against the TTP in 2009. He’s thought to favor force over talks.

Ultimately, the killing of Mehsud may enhance prospects for the very talks Islamabad says his death have shattered.