Inside the decades-long quest to kill al Qaeda leader Ayman al-Zawahiri

US intelligence had hunted al Qaeda leader Ayman al-Zawahiri for decades — then spent several months meticulously planning his death once he was traced to Afghanistan, where he was put up as a guest of the ruling Taliban following the disastrous US withdrawal last year.

The coward who co-planned the Sept. 11 attacks had become the world’s most wanted terrorist soon after his cohort, Osama bin Laden, was killed in a daring US raid in May 2011 — with a $25 million bounty on his head.

Under four presidents, US intelligence operatives hunted al-Zawahiri, who was rumored variously to be in Pakistan’s tribal area or inside Afghanistan.

The CIA came tantalizingly close to possibly capturing al-Zawahiri in 2003, and then killing him in 2004.

The agency thought it finally had him in its sights in 2009, only to be tricked by a double agent who blew himself up, killing seven agency employees and wounding six more in Khost, Afghanistan.