In December 1941, it became apparent to most world naval authorities that battleships would not play the role naval doctrine expected them to play. The vulnerability of battleships to the striking power of aircraft carriers meant that the latter would displace the former as the premier capital ship. However, most navies still possessed an abundance of battleships of various ages and configurations. Through the next three years the navies worked through more and less effective ways of using these legacy warships. The USN did very well, ascertaining that battleships could play an important support role for carriers, as well as provide devastating shore bombardment. The Imperial Japanese Navy did less well, husbanding its battleships for a day of confrontation that never arrived.
What is the modern equivalent of the battleship-as-legacy-weapon? Weapons designed in the 1950’s continue to operate in the preeminent militaries in the Western Pacific, serving alongside systems developed in the digital age. The critical tasks for defense planners are to a) realize that the older weapons no longer play the roles they were intended to play, and b) determine how such weapons can nevertheless find a useful role alongside more technologically advanced systems.
We already know some of the legacy weapons that states could employ in combat in the Western Pacific. One good bet is the non-stealth air superiority and strike fighter. The extant forces of the United States, Japan, China, Russia, and the Koreas include vast numbers of such “legacy” systems. While the F-22 has supplemented Cold War F-15s and F-16s, the latter still compose a substantial portion of the frontline fighting force of the USAF. The ROKAF and the Japanese Air Self Defense Force also continue to use such legacy aircraft in a frontline role. On the (presumptive) other side, it will take a very long time for the PLAAF to replace its legacy systems with the J-20 or J-21, assuming that either design ever reaches production status.
The United States already has considerable experience pressing legacy systems into new roles. The B-1B Lancer, originally intended as a low-level, supersonic strategic penetration bomber, now drops precision guided munitions on small groups of Taliban fighters in Afghanistan. The B-52, which first entered service in the 1950’s, is simply a marvel. More recently, the USN has repurposed several of the Ohio class nuclear ballistic missile submarines for conventional cruise missile missions. The USS Florida, for instance, made a critical contribution to the NATO effort in Libya, supplying cruise missiles for the initial strikes on the Libyan air defense network.
The PLAN is full of legacy systems. While its newest submarines and surface ships appear competitive with some Western designs, ships built or designed before the fall of the Soviet Union (and consequently prior to the flood of Russian technology into China) continue to constitute a substantial portion of the fleet. For example, over a dozen Ming-class submarines (designed during the Cultural Revolution) remain in service, at least in training roles. And as Feng (a blogger at Information Dissemination and China Air and Naval Power) points out, Sovremenny class destroyers and Kilo class submarines purchased from Russia in the early 2000’s remain poorly integrated into the fleet. Determining how such ships could contribute to naval operations poses a major challenge for the PLAN.
When the lifespans of weapons run over half a century (as with the B-52 Stratofortress, the KC-135 tanker, MiG-21, and likely the Nimitz class aircraft carrier), legacy systems present a more imposing problem for future war planners than they did in World War I or World War II. The strategic conditions under which every nation of East Asia operated by even 30 years ago have changed irrevocably, while the weapons remain the same. Determining how to field a force that integrates not only organizations but also generations of systems into a coherent plan of action represents a remarkably complex test for planners (not to mention politicians) on all sides.