SDI (CTP1)

The SDI is a city improvement in Civilization: Call to Power.
== Effect ==
The SDI, the Strategic Defense Initiative, protects cities from nuclear attack within the city's radius. Using a combination of missiles and lasers, the SDI creates an umbrella of safety over the worried citizens of the nuclear age.
== Great Library entry ==
During the 1980s, the American president Ronald Reagan instituted the Strategic Defense Initiative, a multi-billion dollar project whose mission was to protect the U.S. against intercontinental ballistic missiles. Fifty years later, developments in advanced computer tracking and high-energy lasers created a working interception system. Operational for the first time in the middle of the 21st century, SDI arrived just in time to protect the world from nuclear war.
== See also ==
* SDI in other games