The appointment of hardline cleric Mullah Fazlullah as chief of the Pakistan Taleban is likely to mean a period of more bloodshed as he tightens his grip on a faction-ridden group.
To stamp his authority, he will have to avenge the death of his predecessor, Hakimullah Mehsud, who was killed in a US drone strike on Nov 1, analysts say.
"Fazlullah will have to show he is capable and terrorist acts by the group will become necessary," said Dr Ajai Sahni, head of the New Delhi-based Institute of Conflict Management.
"Killings decide the survival of terrorist groups," he told The Straits Times.
That is especially since Fazlullah is the first outsider in a group dominated by the Mehsud clan of Waziristan province.
A compromise candidate after the Mehsuds could not agree on a leader, his immediate priority will be to prevent other leaders from splitting the group.
One of the most feared militant groups in Asia, Fazlullah's Tehreek-e-Taliban Pakistan (TTP) has been blamed for most of the recent attacks in Pakistan, including the assassination of former premier Benazir Bhutto. After Osama bin Laden's death in 2011, the group claimed responsibility for bombing the paramilitary force academy in north-west Pakistan and an assault on a naval base in Karachi.
Thirty-nine-year-old Fazlullah came to be known as the "butcher of Swat" during his rule of the valley between 2007 and 2009, turning the tourist spot into one of the bloodiest as he set up a parallel government and pushed for hardline syariah laws.