This is the big deal. Don't think of it as petty. From nations to individuals, betrayal destroys built trust and changes the landscape. Even Kissinger admits that Trust can maintain an anarchic/international order until the trust is broken.

This is why I'm am a realist, power is more important than Trust, and when you need Trust, use verification mechanisms. This idea is technically an 'Information Hazard' because it causes arms races and costs everyone more resources.