Command unity and surprise in amphibious operations

The book's central warning is that army and navy commanders must understand where responsibility lies at every level of an assault. That clarity must extend from the general and admiral in command to their subordinates. Rival service views and loyalties can otherwise disrupt planning and execution so badly that they become the enemy's allies. Surprise is equally important because an alerted defender can reinforce, fortify, and organize the landing area. Once that preparation time is conceded, an opposed landing becomes much harder to sustain.