mental reservation, n.All

Mental reservation (n.) is ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠the statesman's casuistry: drafting a treaty in words he can reinterpret to his own advantage when the moment suits.