The attack on Pearl Harbor demonstrated the obsolescence of coastal artillery that was not protected against air attack and the inadequacy of pre-war anti-aircraft defenses. However, perhaps if there was no coastal artillery surface raiders would have been bolder. Coastal defense emplacements in the Philippines (the only occasion since the Civil War on which U.S. coast defenses were heavily engaged) and Singapore were locally effective; however, the Japanese simply attacked where there were no defenses and then enveloped the fortifications. Heavily fortified positions such as Japanese Rabaul and Fort Drum in the Philippines demonstrated tactical success amongst strategic failures.