WASHINGTON — Security screeners at two of the nation’s busiest airports failed to find fake bombs hidden on undercover agents posing as passengers in more than 60% of tests last year, according to a classified report obtained by USA TODAY.

While the airport security system seems to have been fantastically effective since 2001 - inasmuch as there have been no major incidents - the question must be asked: Have we been safe because of the system or in spite of the system?