When a state limits its treaty obligations through reservations, other states party to that treaty have the option to accept those reservations, object to them, or object and oppose them. If the state accepts them (or fails to act at all), both the reserving state and the accepting state are relieved of the reserved legal obligation as concerns their legal obligations to each other (accepting the reservation does not change the accepting state's legal obligations as concerns other parties to the treaty). If the state opposes, the parts of the treaty affected by the reservation drop out completely and no longer create any legal obligations on the reserving and accepting state, again only as concerns each other. Finally, if the state objects and opposes, there are no legal obligations under that treaty between those two state parties whatsoever. The objecting and opposing state essentially refuses to acknowledge the reserving state is a party to the treaty at all.
What legal obligations exist between two state parties if one objects and opposes the other's reservations?
no legal obligations