There's zero foundation for trust to uphold an international agreement even between US and its closest allies. Iran has no basis to believe any agreement will be legitimate or upheld.
If you believe the US military, Iran has already lost the majority of its capital-intensive armaments and its nuclear program and its senior leadership. This means there are fewer strategic holdings now at risk. Iran knows it can't be effectively invaded. The regime loses control in two scenarios: (1) internal regime change; (2) diplomatic capitulation to US demands. Waiting out at least US mid-terms while continuing to threaten the strait and neighbor's infrastructure is quite possibly Iran's best decision tree path from the point of view of the regime.