BMD modifications to Standard Missile-2 Block IV updated (Sea-Based Terminal Defense) use upgraded Standard Missile-2 sea-based interceptor missiles to achieve a terminal phase intercept capability.
The FY08 budget request provided funding to begin the near-term and far-term program sea-based terminal program. The near-term sea-based terminal program will modify already existing SM-2 Block IV missiles to address incoming ballistic missiles in the terminal phase.
The far-term program will begin the design and development of a more advanced sea-based terminal capability.

→In all regions provide enhanced engagement capability.
→Engagement capability against missile threats in the terminal flight stage.
→Near-Term SBT provides capability against SRBM and limited PRBM

アンチシップ？
https://www.globalsecurity.org/space/systems/sm2-sbt.htm