In 1962 and 1963, four 1st Infantry Division Pentomic battle groups (2nd Battle Group, 12th Infantry; 1st Battle Group, 13th Infantry; 1st Battle Group, 28th Infantry; and 2d Battle Group, 26th Infantry) rotated, in turn, to West Berlin, Germany to augment the U.S. Army's Berlin Brigade during an international crisis initiated by construction of the Berlin Wall. These "Long Thrust Operations" were the most significant deployments conducted by 1st Infantry Division troops during the Cold War, placing Big Red One troops in confrontation with hostile communist forces.