S.D.I. component

• Modern def. weapon
• Subj. of a 1972 USA-USSR treaty
• 1972 USA-USSR treaty subj
• Air defence sys
• A U.S. missile
• Missile abbr.
• Mil. weapon
• SALT topic
• Anti missile missile (abbr.)

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1963, initialism (acronym) for anti-ballistic missile.