Following the assassination of Hamas leader Ismail Haniyeh in Tehran last week, Israel has vowed to hunt down and eliminate his successor, Yahya Sinwar, who was elected as the new head of Hamas' political bureau on Tuesday.

Israeli Chief of Staff Lieutenant General Herzi Halevi made the threat on Wednesday, August 7, during a visit to a military base in Rehovot, central Israel. Halevi declared that Sinwar, despite his new position, remains "responsible" for planning and executing the October 7, 2023, attack on Israel, known as "Operation Breaking Dawn."

"The change in Sinwar's title motivates us to search for him," Halevi stated. "We will do our utmost to find him and attack him until the head of the political bureau [of Hamas] is replaced again."

Sinwar, 61, has been the leader of Hamas in the Gaza Strip since 2017. He is considered by Israel to be the architect of "Operation Breaking Dawn," which inflicted significant human and military losses on the country and damaged the image of its intelligence and security agencies. Israel has declared his elimination as one of its objectives in the current war on Gaza, dubbed "Operation Iron Swords."

The appointment of Sinwar has been met with mixed reactions. While the American newspaper Washington Post sees it as a "strengthening of his rise as a prominent leader of Hamas," it also raises questions about how Sinwar, who is hiding in Gaza's tunnels and on Israel's wanted list, will fulfill his predecessor's diplomatic duties, including acting as a key negotiator in ceasefire talks, which have stalled following Haniyeh's assassination.

During months of repeated negotiations, Haniyeh traveled between Arab capitals, particularly Cairo and Doha, but Sinwar ultimately had the final say on any agreement. This was confirmed by US Secretary of State Antony Blinken, who stated that Sinwar "was and remains the decisive voice in reaching a ceasefire."

Sinwar played a crucial role in establishing Hamas' military wing and spent over 20 years in Israeli prisons, where he learned Hebrew and honed his reputation among Hamas supporters. He was chosen to replace Haniyeh as Hamas leader in Gaza in 2017, blurring the lines between the movement's political and military wings, according to the Washington Post.

A regional diplomat has suggested that Sinwar's appointment means Israel will have to deal with him to resolve the Gaza war. "It's a message of toughness and no compromise," the diplomat said.

Sinwar has held several security responsibilities throughout his career with Hamas. He participated in the establishment of the movement's security apparatus and was tasked in 1986 with forming the "Mujahid" unit, Hamas' internal security force. This unit plays a critical role in tracking down spies and those connected to Israeli security agencies. Sinwar has been responsible for security and military affairs in Gaza since 2013.

Israeli security officials consider Sinwar to be one of the most hardline members of Hamas and a link between the political leadership and the military wing, the Izz al-Din al-Qassam Brigades, led by Mohammed Deif.