I'll make two points.
First of all, there is reciprocity in terms of the protection of information. The Canada Revenue Agency and the Government of Canada are subject to the same constraints with respect to the use of tax information that it obtains from the U.S. as the U.S. is in relation to information it obtains from Canada.
To your point, if the U.S. does not comply with the agreement, it would be a breach of the agreement. If it were a material breach, it would give the right to terminate. That would be the rights as between governments.