That meant drawing up adequate but simple designs, reaching out to as broad an array of manufacturers as possible—think Detroit auto factories retooling to churn out a finished B-24 bomber every hour—and getting the biggest head start possible. The U.S. Navy embraced a satisficing attitude that’s worth rediscovering. It also started regenerating combat power before it lost any. Thanks to sage leadership in Congress and the Franklin Roosevelt administration, builders started riveting new ships and planes together not after Japanese aviators rained destruction on Pearl Harbor in 1941, but a year before under the Two-Ocean Navy Act of 1940.

Preemptive reconstruction of battle strength ought to be the watchword for U.S. fleet architecture from now on. And there’s one final advantage to building up reserve capacity: it empowers fleet commanders to handle the existing fleet aggressively at the outbreak of war rather than act cautiously to conserve irreplaceable assets. Knowing replacement ships and planes are on the way lets commanders court risk—much as Admiral Chester Nimitz could fling the remains of the Pearl Harbor fleet into aircraft-carrier raids in 1942, knowing a brand-new U.S. Navy would arrive in Pacific waters starting in 1943. If you have a spare, why not risk what’s on hand in hopes of scoring a major triumph?

So there you have diplomatic, strategic, budgetary, operational, and tactical reasons for acquiring diesel submarines to augment the existing nuclear fleet. Let’s get to it.

James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College and coauthor of Red Star over the Pacific.