Problem
In 2005 South Africa and Mozambique conclude a treaty governing visa requirements for their respective citizens to visit each other's countries. After discussions in 2007, a new treaty in which they provide that visas will no longer be required for cross-border visits is concluded. This new treaty makes no mention of the 2005 treaty. John Smith arrives at the Mozambique border post in his 4X4 towing his speedboat, but is denied entry by the Mozambique immigration officer as he has no visa. Discuss what a treaty is and which treaty will apply and why?