On March 1, 1996, by Proclamation 6867, a national emergency was declared to address the disturbance or threatened disturbance of international relations caused by the February 24, 1996, destruction by the Cuban government of two unarmed U.S.-registered civilian aircraft in international airspace north of Cuba. On February 26, 2004, by Proclamation 7757, the national emergency was extended and its scope was expanded to deny monetary and material support to the Cuban government. The Cuban government has not demonstrated that it will refrain from the use of excessive force against U.S. vessels or aircraft that may engage in memorial activities or peaceful protest north of Cuba.
Less than a month after this exchange on July 16, 2013 the Castro regime was discovered smuggling a ship load of weapons hidden under bags of sugar that included MiG fighter jets, rockets, and ballistic missile technology to North Korea in violation of international sanctions.
The bottom line is that seeking to normalize relations with an abnormal regime is a recipe for failure not to mention cognitive dissonance. The Bush policy on North Korea being a recent and cautionary example.