Tzeirei Agudas Chabad (Tzach) is the Chabad youth organization in Eretz Yisrael, responsible for outreach and spreading Chassidus. These letters are addressed to its executive committee in Jerusalem, and span roughly 5714–5723 (1954–1963). See also Land of Israel – Jerusalem.
Leadership and teamwork. The Rebbe wrote that leadership is both a profound responsibility and a great merit (IK 4118), urged immediate renewal of practical efforts and cooperation between organizations (IK 4119), and taught that centralizing communal work increases its effectiveness and reduces wasted effort (IK 3478). When called on for urgent action in our time, he wrote, all the necessary strength is granted from Above (IK 5382).
Outreach and campaigns. The letters ask for timely reports on practical work, such as the shmurah matzah campaign (IK 4264), and for using special times — Purim, Chanukah, Yud-Beis–Yud-Gimmel Tammuz, the Baal Shem Tov's yahrzeit — for spreading Chassidus (IK 2489, 4522, 4973, 7179). Effective outreach requires both collaboration and discretion (IK 7986), and heartfelt dedication expressed in daily action (IK 8762).
Sources: the Rebbe's letters cited above.