Barack Obama improved US relations with Iran and Cuba

The UN has imposed economic sanctions on Iran since 2006, claiming that it is secretly manufacturing nuclear weapons. Iran's economy has been crippled as a result of the sanctions. After much back and forth, and primarily due to President Obama's perseverance, Iran and the P5+1 (China, Russia, France, the United Kingdom, the United States, Germany, and the European Union) signed the Joint Comprehensive Plan of Action.

The Iran Nuclear Deal, as it's known, removed sanctions in exchange for Iran agreeing to curb its sensitive nuclear activity and allow foreign inspectors into the country. Apart from the Iran Nuclear Deal, Obama made history in March 2016 when he visited Cuba for the first time since 1928. Moreover, along with Cuban President Raul Castro, he announced on December 17th, 2014, that a process of normalizing relations between Cuba and the U.S. would be started. This announcement ended a 54-year stretch of hostility between the nations.