Nagumo belonged to a Fleet Faction that wanted Japan to receive at least 70 percent of the strength allotted to the leading naval powers under the Washington treaty, a 7:10 ratio instead of 3:5. Nagumo was one of the rising senior officers who could succeed the faction's ageing leadership. His first rear-admiral assignment to the new Mogami-class 8th Cruiser Division demonstrated institutional trust in his ability. The cruisers' manoeuvrability and firepower made them valuable to an attrition campaign against an enemy's lighter forces. He subsequently commanded the torpedo school and the 3rd Cruiser Division, extending his experience in the weapons and formations central to that doctrine.
Chapter · 30:35-36:20
Fleet politics and command of the Mogamis
Nagumo's opposition to the Washington treaty ratio accompanied prestigious commands of new Mogami-class cruisers, the torpedo school, and increasingly senior cruiser formations.