Commentary “When these attacks occur, as they likely will, we will wonder what more we could have done to stop them.” That was National Counterterrorism Coordinator Richard Clarke, in a May 29, 2001 memo to National Security Advisor Condoleezza Rice and her deputy Stephen Hadley. The statement, which warned that “hundreds” of Americans might be killed, may be found in “The 9/11 Commission Report: Final Report of the National Commission on Terrorist Attacks Upon the United States,” published in 2004. “It is perhaps obvious to state that terrorists cannot plan and carry out attacks in the United States if they are unable to enter the country.” That is from the introduction to “9/11 and Terrorist Travel: Staff Report of the National Commission on Terrorist Attacks Upon the United States.” This document was released separately from Commission report. As the staff report shows, by this time 20 years ago, the al …