One of the powers that fought Earth's Third World War, known as the ECON, which the survivors at Zefram Cochrane's Montana camp blamed for the Borg attack of 2063.
The Eastern Coalition, or ECON, is one of the factions of the Third World War, the nuclear conflict that devastated Earth in the middle of the twenty-first century. Very little is said of it beyond its name.
It is mentioned in Star Trek: First Contact. When the Borg sphere fires on the missile complex in Montana where Zefram Cochrane is preparing the Phoenix, Lily Sloane assumes that the Eastern Coalition has broken the ceasefire. She clings to that belief after being beamed to the Enterprise-E, accusing Picard of belonging to an enemy faction until he shows her the Earth from orbit.
The reference places Cochrane's flight in a world still divided and suspicious, a decade after the war, which the first contact with the Vulcans would begin to change.