Lack of trust is a symptom not the cause. I hate it when I hear politicians and the like bemoan a "lack of trust". I don't want to trust you! I want to hold you to account!
Deliberately conflating cause & effect is a classic politician’s move. It doesn’t even have to be a reversal of the two: it’s probably even more frequent when they cite one part of a positive feedback loop as the unambiguous cause and the other as the clear effect.
The classic example of the later are the politicians who rant “if only these people would get married and stay married, they wouldn’t be so poor” and neglect to consider that impoverished communities create the conditions for rampant single motherhood. The desire to raise children does not magically vanish merely because there are exactly zero worthwhile men in your community that aren’t your father’s age.
Actually trust is both a symptom and a cause. The causality goes both ways.
(1) If you lose trust in someone, you'll be less likely to try to find truth in their statements. Finding truth in someone's statements requires time and attention, and we'll invest that attention in people we trust.
(2) If you find falsehoods in their statements, you will lose trust in them.
Overall in Psychology, trust is a primary indicator of a relationship, marriage, partnership, or organization succeeding or falling apart. It's both a symptom and a cause of all other factors.