"Without trust, the team environment is stillborn," he wrote in British newspaper the Sunday Times.
"It is for this reason that Kevin Pietersen's international career had to be brought to an end.
"The media have been searching for a 'smoking gun'. Everyone is looking for disciplinary problems, bust-ups and character clashes, but they are looking for the wrong thing.
"The smoking gun is the total absence of trust."
Strauss identified Pietersen's dismissal as England captain five years ago as the beginning of the breakdown.
"It is for this reason that Kevin Pietersen's international career had to be brought to an end.
"The media have been searching for a 'smoking gun'. Everyone is looking for disciplinary problems, bust-ups and character clashes, but they are looking for the wrong thing.
"The smoking gun is the total absence of trust."
Strauss identified Pietersen's dismissal as England captain five years ago as the beginning of the breakdown.
