The Conservative Movement in the United States grew in the late 20th century, bringing together groups focused on limited government, traditional social values, and free market policies. Ronald Reagan successfully harnessed this movement when he was elected president in 1980 and 1984, pursuing tax cuts, increased defense spending, and deregulation of the economy. However, his policies also increased the national debt substantially. Reagan faced some foreign policy challenges like the Iran-Contra affair and terrorist attacks, but also had some diplomatic successes by engaging with Soviet leader Mikhail Gorbachev.