Biden says intelligence community doesn't trust Trump as he has "no conception" of national security

During an interview with CNN, Democratic presidential nominee Joe Biden told Jake Tapper that President Donald Trump "seems to have no conception of what constitutes national security". This statement refers to Trump telling Bob Woodward about existence of a classified nuclear weapons system.
"You wonder why people in the intelligence community wondered from the very beginning whether you could share data with him, 'cause they don't trust him. They don't trust what he'll say or do," so Biden to Tapper. "He seems to have no conception of what constitutes national security, no conception of anything other than, what can he do to promote himself?"