Eighteen years after the physical and emotional devastation the al-Qaida attacks inflicted on the U.S. on Sept. 11, 2001, the haunting images — of planes crashing into buildings, of people jumping out of World Trade Center windows — still evoke a deep sadness in many Americans.

In this edition of The Hunt with WTOP national security correspondent J.J. Green, retired CIA senior intelligence service official Douglas Wise says that hard day led to a hard choice.