There is no reason to believe that yet more years of sanctions will make a difference. Cuba has been defiant in the face of much worse and continued on the same course. The sanctions cannot provide leverage while other states do not have sanctions; Cuba can get anything it requires from elsewhere without recourse to the United States so why would Cuba be willing to ever make concessions before sanctions are dropped. [1]  [1] Reeson, Greg, ‘Time to Drop Sanctions Against Cuba’, 2006.