Why did Tiberius avoid major new conquests during his reign?

Tiberius sought to preserve the imperial institutions and boundaries established by his predecessor, Augustus. His avoidance of major new conquests was largely a continuation of the policy adopted by Augustus toward the end of his own reign.12

Following the catastrophic Battle of the Teutoburg Forest in 9 ce, where three Roman legions were destroyed, Augustus became disheartened and decided against further expansion, a strategy he explicitly urged Tiberius to follow. Consequently, Tiberius focused on consolidating the empire's existing frontiers, particularly along the Rhine and Danube rivers, rather than pursuing territorial growth. While he maintained Roman influence in regions like Armenia, his administration prioritized stability and the management of the existing empire over the risks and expenses associated with new annexations.32