Fimbulwinter Protocol

Strategic relativistic attack plan developed by the United States of Eisenhower during the Second Interstellar Period. It called for carpet-bombing all major landmasses on the target world with RKVs over a period of one local day, obliterating all surface settlements and ensuring enough dust would be thrown into the atmosphere to block out the sun for years, wiping out all natural food sources.
In the Age of Strife, the Fimbulwinter Protocol depopulated the Celestial Union world Yushan. Eisenhower was hit by a similar counterattack and its civilization likewise assumed eradicated.