Thank you for the opportunity to help you with your question!
To have a good treaty, there are certain considerations that a country should have in mind. The treaty should be beneficial to both parties and should also be understood by both the parties that are signing it. The contents of the treaty should be doable and realistic to both parties. Another factor that strengthens the treaty is when it is well explained.
When a country is worried that the other country might break the treaty, they should consider that in the first place, the treaty is beneficial to both parties. To this effect, they can try convince and keep reminding the other party that they stand to benefit from the treaty. If this does not work, then that country should cushion itself in the case that the others break the treaty. The country should prepare just in case it has to impose sanctions and take other measures that would entail maybe the withdrawal of services and other relations between these countries. The country should also inform any body that might have been responsible for the signing of the treaty. Perhaps the move that body would make is to send a delegation to the country that seems likely to withdraw from the treaty to determine the situation first hand.
Please let me know if you need any clarification. I'm always happy to answer your questions.