Trust is built through effective commitments. Trust is lost through inconsistent behavior on matters of importance. If trust has been cultivated and grown over time … the project will be highly resilient to problems. - Scott Berkun, The Art of Project Management, Chapter 12, O’Reilly, 2005
When we hear trust is needed, it's important to know that trust is earned by consistent behavior. As Scott suggests, consistency in meeting commitments is the basis of trust.
The open question is - as always - can you make a commitment and take actions toward meeting that commitment in the presence of uncertainty without estimating the reducible and irreducible uncertainties to take corrective and preventative actions to increase the probability of success in meeting these commitments?