In a prelude to the offensive, Sperrle planned to carry out strategic bombing operations against Paris. Sperrle had long-planned for air attacks on Paris using II., V. and VIII. "Fliegerkorps" in May. He was forced to abandon the plan on 22 May because of weather, but the following day, the OKL prepared a plan for Operation Paula. The plan was to attack the estimated 1,000 French aircraft detected on Parisian airfields, but also to attack factories and destroy the morale of the French people. The operation was undone by poor staff work and excessive confidence in the Enigma machine. ULTRA intercepted a VIII. "Fliegerkorps" message to KG 77's commanding officer, which named Paris as the target. The ZOAN increased its operational strength to 120 fighters and were alerted an hour before the German bombers got airborne. The operation inflicted minor damage.