Military . the key group of officers and enlisted personnel necessary to establish and train a new military unit.

a group of trained or otherwise qualified personnel capable of forming, training, or leading an expanded organization, as a religious or political faction, or a skilled work force

They hoped to form a cadre of veteran party members.

(esp. in Communist countries) a cell of trained and devoted workers.

a member of a cadre; a person qualified to serve in a cadre.

a framework, outline, or scheme.

noun

core , force , framework , infrastructure , key group , officers , organization , personnel , staff , frame , group , nucleus , panel , unit