U.S. President Joe Biden announced Monday evening that al-Qaida leader Ayman al-Zawahiri had been killed in a drone strike in Kabul, Afghanistan.Al-Zawahiri was appointed in June 2011 to succeed Osama bin Laden as the leader of al-Qaida, one month after bin Laden was shot and killed by U.S. forces in Abbottabad, Pakistan.U.S. President Joe Biden announced Monday evening that al-Qaida leader Ayman al-Zawahiri had been killed in a drone strike in Kabul, Afghanistan.Al-Zawahiri was appointed in June 2011 to succeed Osama bin Laden as the leader of al-Qaida, one month after bin Laden was shot and killed by U.S. forces in Abbottabad, Pakistan.