When President Trump signed the 2018 omnibus spending bill, he committed the nation to a two-year, $1.416 trillion defense-spending plan, but his signature did not answer the larger question that has been hanging over the defense debate: Should the nation invest in increased lethal capabilities — that is, more technical solutions such as stealth aircraft and more precise intelligence-surveillance-reconnaissance systems — or expand capacity, otherwise known as growing the force? The new national-security strategy issued by the White House in December and the national-defense strategy released by the Pentagon in January both endorse building capacity — increasing the number of personnel and ships, aircraft, and vehicles overall — as a strategic goal, although the Pentagon document is muted in its phrasing.
However, capabilities proponents, from both the right and the left, make arguments, from fiscal and technology perspectives, that it is no longer possible or necessary to maintain large numbers of troops, tanks, aircraft, and ships in the active force. They advocate instead a smaller but more lethal force centered around advanced capabilities. Voices from the expanded-capacity school argue that a generation of investment in exquisite capabilities has resulted in a diminished force that is too small to maintain the peace or win a war. They advocate significantly increased defense budgets, such as the one just approved, and a larger overall force that includes a bigger Army, Air Force, and Navy.
These approaches — increased capabilities and expanded capacity — appear greatly at odds with each other and draw on dissimilar assumptions regarding the global security environment. Each deserves an honest, objective examination. Is some balance between the two approaches possible?
Increase capabilities: The capabilities school has been the predominant voice in the internal American defense debate for much of the past two generations. Beginning in the 1970s, as America exited the Vietnam War and support for defense spending waned, the Carter administration pivoted toward a new strategy that sought to capitalize on new capabilities that had emerged near the end of the hostilities in Southeast Asia.
Much as Eisenhower had pushed reliance on nuclear weapons during the 1950s as part of a “new look,” seeking to defend the nation at a lower cost, Harold Brown and William Perry — Carter’s secretary of defense and undersecretary of defense for research — pursued precision-strike architecture consisting of stealth aircraft, a space-based global-positioning system, and a constellation of precision-strike weapons. There were other improvements as well: the development of the heavily armored, high-speed M1A Abrams tank for the Army and the Mk 7 Aegis combat system for the Navy. Each represented a generational leap-ahead capability over peer competitors but also came with strikingly higher individual-unit costs. The strategic bet was that in battle each new system’s higher lethality would allow it to strike with more accuracy at greater range, and this approach in war has been proven largely correct.
Modern observers today characterize the Desert Shield–Desert Storm campaign of 1990–91 as a lopsided battle, and it was. More than 25,000 Iraqi troops were killed, while the American-led coalition suffered only 147 deaths, and Saddam Hussein’s army was pushed out of Kuwait in just 100 hours of ground combat. The victory stunned the world, causing Russia and China to note America’s significant technological advances. However, before battle had begun, U.S. commanders had no realistic foreshadowing of the dramatic victory. Given that the United States and its partners were facing one of the world’s largest and most experienced armies, which had just spent a decade battling Iran, expectations were that the U.S. would suffer approximately 30,000 casualties. President George H. W. Bush agonized over that in prayer before committing U.S. ground forces to battle.
Post-war analysis sent a chill through the international community. Previously an entire squadron of aircraft would be launched to take out a single critical target. During Desert Shield–Desert Storm, however, a single aircraft loaded with four “smart” precision-strike bombs might be launched with the expectation of hitting four bull’s-eyes. Moreover, stealth technology provided the potential for accomplishing each mission without detection by enemy defensive systems. Global precision systems and precision strike gave rise to a new slogan in American warfare: “We do windows.” American targeteers could now be more selective.
Reverberations caused by America’s success in the desert continued throughout the following year, as the Soviet Union dissolved in December 1991 and the Cold War came to an end. Faced with an ideological victory over Communism and with the “end of history,” the United States and its allies pursued “peace dividends” and reduced their defense spending dramatically.
In the United States, defense budgets as a percentage of the nation’s gross domestic product had fallen from 5.5 percent in 1991 to 3 percent on the eve of the attacks on September 11, 2001. Key capacities fell accordingly. In 1991 the Army stood at 710,000 troops; in 2001, it had shrunk to 480,000. At the height of the Cold War, the Air Force fielded over 10,000 aircraft; today the force hovers around 6,000, with fewer than 4,000 planes prepared for combat. The Navy suffered a similar decline, shrinking from its peak of 592 ships in 1989 to its present level of 280. To be sure, all decreases represent policy that has been bipartisan. It was based on the assumption that the forces that remained would be more lethal than in the past. That assumption was convenient for policymakers who wanted to shift spending from defense to entitlements.
In 1971, Social Security, Medicare, and Medicaid, often designated as “mandatory” spending programs, accounted for 4.8 percent of the nation’s gross domestic product and less than half of the federal budget. Today they represent over 10 percent of GDP and nearly 70 percent of federal spending. Discretionary spending — that is, spending on all other items in the federal budget — shrank accordingly, with defense spending falling from 32 percent of the budget in 1987 to approximately 19 percent today. Entitlement programs as well as the poorly conceived 2011 Budget Control Act constricted defense spending even as external global threats rose. The underlying strategic assumption remained: As long as the nation maintained its edge in high-tech capabilities through advanced research and development, we could expect to maintain what we had labored so long to build, our leading position in the world. But we didn’t, and that is where the capacity proponents enter the debate.
Expand capacity: When the nation embarked on its pursuit of what is now recognized as its “Second Offset,” during the Carter administration, it was sitting on a sizable Army, Navy, Marine Corps, and Air Force, and did not enact force reductions overnight. Instead it slowly “bled off” its older, less capable forces, decommissioning three Knox-class frigates for each new Ticonderoga-class cruiser, or striking four F-4 Phantom jets from the Air Force’s inventory for each new F-15 Eagle. In the end, the services managed smoothly the turnover from older, more numerous, but less costly platforms to newer, fewer, higher-capability weapons, until 2003–05, when uniformed defense leaders realized that they no longer had enough troops, ships, and aircraft to meet the demands of wars in Iraq and Afghanistan while also supporting national interests elsewhere. The massive increases in defense spending that followed 9/11 were consumed by operational demands in war zones, leaving no funds to buy additional big-ticket platforms.
An assumption behind arguments for the “higher capabilities, smaller force” school has always been that when global storm clouds gathered, national political leaders would turn on the spigot of defense spending, but 9/11 and Iraq coincided with a period of a large national debt and an aversion to higher tax rates. Fiscal hawks moved to block big-spending defense hawks.
A point that is often not well understood is that both ships and aircraft can be used only for so long before they become materially compromised. Aircraft longevity is measured in “wing life,” as the stresses of high-performance flying degrade the roots of the aircraft wings, where they join the plane’s main body. Similarly, ships are exposed to weather, saltwater, and the forces of the sea, which weaken the structural integrity of the hulls over time. That is normal and anticipated in building plans for both aircraft and ships.
But during wartime, craft are flown and sailed more than usual. They reach the end of their operational lifespan before their planned retirement dates. If high costs prohibit the services from replacing them as they retire, then the fewer remaining ships and aircraft must sail or fly more to the same number of missions, accelerating their demise. If that process continues unabated, the force enters a death spiral, in which the smaller number of platforms in service are used up at ever-increasing rates, resulting in the accelerated depletion of the inventory. Such a spiral is difficult to pull out of without dramatically increased spending, especially when all the ships and aircraft being bought are the most complex and expensive in the world.
The result is a steadily shrinking force that can no longer remain forward-deployed in all of the regions of the world where the United States has established interests. As the U.S. pulls back to preserve its forces, local actors begin to change their attitudes and activities. Friends begin to doubt American commitment and tip away from economic and security agreements. Enemies sense a vacuum and move to establish their influence. Such is the way a global system of governance can disintegrate.
A strategy that avoids this outcome entails a balanced ratio of high-end capabilities and low-end capacities: a “hi-lo” mix. For example, rather than buy two fifth-generation stealth fighter aircraft, Navy and Air Force secretaries could buy one advanced aircraft and two or three less complex aircraft for the same price. Similarly, naval-fleet architects could pursue one advanced air-defense destroyer and three anti-submarine frigates and general-purpose offshore patrol vessels rather than pursue two high-end destroyers. This approach makes even more sense when we consider that most day-to-day missions do not need the most advanced and complex platforms. You don’t use a farming tractor to mow your lawn. It would be equally unwise to use the most advanced fifth-generation fighter in the world to destroy white Toyota pickup trucks in a Middle Eastern desert.
Capacity is best understood in light of this question: How many ships, aircraft, and personnel does the United States need to provide sufficient military presence to protect our national interests on a daily basis? Too few can mean the low readiness, the poor material condition, the accidents, and the peacetime deaths that the Navy has experienced in the past year. It’s tasked to provide an average of 108 ships forward-deployed on peacetime-presence patrols in 18 regions identified by combatant commanders. The minimum number of ships required is 355, some 75 more than the current fleet of 280. For the Air Force, demands of regional combatant commanders drive the number of combat-ready aircraft that are required to around 4,700, with a notable increase in the demand for long-range heavy bombers, given the rise of anti-access/area-denial technologies. These are the numbers required to maintain the current global stability that the United States labored to establish following World War II.
The passage of a two-year defense authorization does not spell the end of the debate about how much we should spend on defense. After all, some 16 Republican senators and 67 Republican House members voted against the bill. Defense strategists should call on the wisdom of the past and seek maximum fiscal efficiency through a balance between capability and capacity. Overemphasis on high-end capabilities has led to the current crisis with respect to readiness, maintenance, and presence. That in turn has invited great-power competition. Likewise, overemphasis on capacity — on large numbers of peacetime-presence, low-end platforms — could lead global competitors to calculate that they could win the next war with only a modest number of high-end platforms of their own. The ideal solution is a balance, a hi-lo mix of war-winning capabilities and peace-preserving capacity.