The next one on deck had better watch his neck.

While Egyptian doctor Ayman Al-Zawahiri is al Qaeda’s No. 2 terror fiend, he is not considered a sure-thing successor to Osama bin Laden.

Another contender, Saif al-Aldel, al Qaeda’s military commander, was a likely key player in the 1998 African embassy bombings.

A third possibility, ex-bin Laden aide Nasser Abdul Karim al-Wuhayshi, runs al Qaeda’s branch on the Arabian peninsula.