On Monday, Biden said that Zawahiri had “made videos, including in recent weeks, calling for his followers to attack the United States and our allies.” If he was known to be in Kabul in May, and made videos urging his followers to kill Americans in “recent weeks,” that means Zawahiri was planning and inciting external operations against the United States from Afghanistan, possibly under the protection of the Taliban. That might not have been possible if Biden had listened to his military commanders and left a residual U.S. force in Afghanistan, preventing the Taliban’s return to power.

A critical question now is what operations was Zawahiri planning? Unfortunately, we might never know. Unlike the 2011 raid that killed bin Laden, the operation that killed Zawahiri was not carried out by a team of U.S. Special Operations forces. That’s because, thanks to Biden, the United States no longer has boots on the ground. Zawahiri had to be taken out by drone strike, which means we had no ability to exploit the site where Zawahiri was killed by collecting pocket litter, computers, hard drives, cellphones, documents or other material intelligence. The bin Laden raid produced a trove of information on al-Qaeda’s operations, ongoing plots, the identities and locations of al-Qaeda personnel and other vital actionable intelligence. The drone strike that vaporized Zawahiri destroyed all the actionable intelligence he possessed along with him.