Achieving “peace through strength” in the 2020s

The context: Defense strategy in the era of great-power rivalry

The United States Armed Forces, and the broader national security community, have been emerging from the era of the “war on terror” and shifting to a greater focus on great-power competition for about a decade now. This context is important—for understanding what Trump already prioritized in his first term, for seeing the continuity in defense policy over much of the past 10 years, and for appreciating that change at DOD comes slowly and requires patience as well as persistence.

The transformation really began when the late Ash Carter became secretary of defense in 2015. General Joseph Dunford and General Paul Selva took over the chairman and vice chairman jobs at DOD that same year. Together, the team coined the phrase “4+1” to emphasize that going forward, the United States DOD would not be riveted just on the threats of rogue states and terrorists but on five dangers: Russia, China, North Korea, Iran, and transnational violent extremists. There was also a growing awareness that conflict against one of the larger powers might not be confined to the region within which it began. U.S. forces remained in Afghanistan but in much smaller numbers and with a redefined mission intended primarily to provide support to the Afghan military; operations against the Islamic State, which had begun the year before, continued (and would be expanded) but were limited to aerial operations and some training and special-forces missions. The main muscles, bones, sensory systems, and neural pathways of the American armed forces shifted more and more to Russia and China—especially after the former seized Crimea in 2014, and the latter accelerated major modernizations of its armed forces while also militarizing the South China Sea despite Xi Jinping’s earlier promise to Barack Obama that it would not do so.

The full articulation of the changes in both American grand strategy and defense strategy would happen in the Trump administration, with the release of the H.R. McMaster-directed National Security Strategy of late 2017 as well as the Jim Mattis-directed National Defense Strategy of early 2018. Trump blessed the essence of what his national security advisor and secretary of defense wanted to do with these landmark national security documents. They would have a major legacy, as it turned out—and their main ideas would survive into the Biden administration with much more continuity than one might have expected given the sharp political differences between Trump and Biden.

Mattis’ 2018 National Defense Strategy (NDS), authored in part by Elbridge Colby, Trump’s newly nominated undersecretary of defense for policy, and later also implemented by Secretary of Defense Mark Esper, focused on both Russia and China. Mattis also emphasized the paramount priority that must be given to improving U.S. military lethality, just as Hegseth has done in his first weeks in office. Mattis did not propose an expansion of the force; the size and relative composition of the American armed forces have remained remarkably constant over the last 30 years (with only a limited and temporary buildup of the Army during the 2000s as the main exception to this generalization). As such, under the 2018 NDS, the United States stated that it would seek the capacity to defeat either Russia or China, but not both at the same time. The two-war paradigm that had dominated American defense planning for decades was largely gone—even if the basic force structure and global posture of the American armed forces did not change dramatically as a result. Mattis sought to improve military readiness, but even more to hasten modernization across numerous areas of defense technology, many of them pertaining to offensive operations—such as hypersonic weapons, robotics, nuclear weapons, attack submarines, fighter jets, and stealth bombers. He called for annual real-dollar increases in defense spending of 3% to 5% to demonstrate American commitment to competing with Moscow and Beijing and to resource the planned investments, saying that the nation “can afford survival.” Defensive weapons such as missile defense systems were also emphasized; so were more resilient satellite constellations and computer networks.

Four years later, the Austin Pentagon would retain almost all of these priorities. Its 2022 NDS would prioritize China, describing it as the “pacing challenge.” Russia was recognized as an “acute threat,” given its aggression against Ukraine. Austin also emphasized resilience and survivability, to go along with lethality—but in programmatic terms, the same range of new systems was effectively still on the Pentagon’s shopping list. Force structure, as well as global basing and deployments, remained largely as before, somewhat belying the notion that there had been a fundamental change in grand strategy—though Army recruiting challenges led to a 10% reduction in active-duty soldiers. Although inadvertent, this reduction was nonetheless consistent with the change in strategy, since large formations of Army combat forces, while still crucial, are probably somewhat less central for a maritime-centered fight against China than are the capabilities of the other military services. (It is worth remembering, though, that the United States still remains treaty-bound to help defend allies in Europe and Korea where large-scale ground combat operations could occur; national defense strategies only have so much ability to remake radically and quickly the American armed forces.)

In budgetary terms, during the Trump presidency, real-dollar defense budgets increased about 3% per year under both the 115th and 116th Congresses. Biden, as well as the 117th and 118th Congresses, kept inflation-adjusted budgets more or less flat (though at that higher level achieved by Trump). Some of the key architects of Mattis’ 2018 NDS have expressed concern that with all the modernization priorities laid out in that plan and its successor, budgetary resources have not been adequate for the task; so in that sense, there is not complete continuity from the 2018 NDS to the 2022 NDS to today.

The greatest DOD innovators over the last decade have probably been the Marines. While commandant of the Marine Corps, now-retired General David Berger shook the defense establishment with several big changes. His goals, and those of his successor, General Eric Smith, have been to make the Marines more focused on China and the Pacific—and therefore more expeditionary; less dependent on centralized command, control, communications, and intelligence support; less dependent on large bases as well as big (and vulnerable) ships; and more lethal, especially in the realm of long-range missile strikes. They have eliminated tanks and deemphasized unguided artillery, diversified the footprint of Marines in the Asia-Pacific region in particular, and equipped new “littoral combat regiments” with anti-ship missiles as well as their own sensor and communications networks to reduce dependence on satellites. These ideas are linked through the Marines’ Expeditionary Advanced Base Operations concept.

Other key innovations in recent years include the creation of the Space Force in 2019, a major Trump priority that gained considerable bipartisan support. They also include the Air Force’s concept of Agile Combat Employment and the ensuing (modest, but real) diversification of its basing posture in the Indo-Pacific region. The strategic goals include helping joint-force commanders better monitor and attempt to deter China from various “gray zone” micro-aggressions as well as larger attacks in places like Taiwan. The Army and Air Force together have led the charge on “JAD-C2”—joint all-domain command and control efforts that have sought to make sensors and communications grids more agile and survivable. The concept has now been expanded, for those who like to track the actual origins and meaning of Pentagon acronyms, to CJADC2, with the first letter standing for “combined” and underscoring the need to involve allies in the effort as well. The most impressive, actual physical manifestation of this new concept to date is probably in increasingly redundant and survivable satellite networks.

So there has been lots of positive movement at DOD over the past decade. But there is clearly much more to do, starting with the premise that it is no longer quite so reasonable to assume that a one-war capability is adequate for the United States. Moscow, Beijing, Pyongyang, and Tehran coordinate much too closely these days for any such paradigm to be adequate.

Toward a “win one war, hold/defend in three” planning paradigm

One big new defense debate began to brew in 2024: how to think about, and plan for, the possibility of more than one war happening at a time. This was a central conclusion of the landmark report of the 2024 independent Commission on the National Defense Strategy, with solid logic and good reasoning behind it. The next U.S. national defense strategy should rethink this important question.

Like the Trump National Defense Strategy as developed by Mattis and further implemented by Esper, the Biden NDS under Austin establishes the following key objectives for the American armed forces:

• To be able to fight, together with at least some allies, and defeat China or Russia—but not both at the same time.
• To defend the American homeland while also maintaining a ready nuclear deterrent.
• To deter North Korea and Iran.
• To maintain momentum against transnational violent extremist organizations as part of the so-called “war on terror.”

Yet the assumption that it is enough to be able to fight and win one war at a time seems questionable in light of the growing strategic cooperation and coordination between Russia, North Korea, Iran, and China. Simultaneous or overlapping crises, even conflicts, are hard to dismiss as a possibility. That is not to say that the nation will move from its current “one-war” force-sizing paradigm to a 1.5-war or two-war framework, as in previous eras. But the United States needs to think hard about how to best deter several potential adversaries at once. Specifically, it needs to change the possible perception that, if engaged in a single war, say against China, the United States and regional allies would be left defenseless elsewhere. Any such perception, even if a misperception, could raise the risks of opportunistic aggression.

I propose that the United States adopt a policy of simultaneously limiting damage and denying enemy advances in multiple theaters while maintaining the ability to win a single big war at the same time. In particular, were the United States to fight China over Taiwan—probably the most militarily stressful scenario that can be plausibly postulated today—it should be able to leave forces in other theaters that could achieve the following goals:

• In the Middle East, we need to have the kinds of defensive capabilities in place that were used to help shoot down 300+ Iranian missiles and drones on April 13 and October 1, 2024. The United States has often used two aircraft carriers plus land-based assets in these tasks. Aircraft carrier battle groups are an expensive way to do this job; building a dedicated fleet that could always keep two carriers in the region without being homeported there would literally require building eight more, given ship rotation demands. That would lead to a whopping average annual price tag, including procurement as well as operating and personnel costs, of around $50 billion. Moreover, the United States could not plausibly build that many added ships until the 2030s even if it went all-out.

  However, adding the equivalent capability in dedicated land-based air and missile defense systems, to be kept in the Middle East under all circumstances—even in the event of war with China—should have an average annual cost of $5 billion or less, based on the costs of systems like the Terminal High Altitude Area Defense (THAAD) and AEGIS radar/Standard Missile air and missile defense systems to date. (Costs would likely be greater at the beginning, however, as interceptors, radars, and control centers were procured and built.)

• With North Korea, the goal of any “hold” strategy should be to help the Republic of Korea (ROK) defend itself from air, missile, artillery, and drone attacks on Seoul in particular while having enough U.S. airpower to help the ROK go after the North Korean launchers and weapons depots (including any for nuclear weapons that we can identify) early in a war. Those tasks should not have to await the resolution of the postulated U.S.-China war. Fortunately, we already have nearly 30,000 U.S. troops in South Korea today and they have most of these capabilities. However, they might be required for the conflict against China that is assumed to be already underway. At a minimum, therefore, we would need the ability to bring additional airpower and air/missile defense systems to the Korean Peninsula in time of war over Taiwan comparable in capability to what is already there. That might entail four more squadrons of combat aircraft and four more Patriot or THAAD defense batteries.

  A squadron of fighter aircraft, according to the Congressional Budget Office, costs $600 million to $800 million a year in operations and support costs. To buy the aircraft for a squadron with a dozen planes costs roughly $1 billion, not dissimilar to the cost of the equipment in a THAAD battery. Thus, assuming South Korea pays most of the local construction costs, this kind of initiative could require some $10 billion in initial investment and then cost about $5 billion a year in operating and support costs into the future. (If one amortizes or averages the investment costs over a 20-year typical equipment lifetime, the average annual cost of this initiative counting everything would be around $6 billion a year.)

• With Russia, the United States should station real American combat power in NATO’s most exposed eastern flank—the Baltic states. The idea would again be to discourage a rapid enemy assault, in this case, perhaps against the eastern parts of Estonia and Latvia, where there are lots of Russian speakers whom Vladimir Putin has claimed the right to “protect.”

  Adding one Army brigade combat team (about 3,500 soldiers formally within the brigade combat team, plus up to three times as many in support units) and a combat aviation brigade to the permanent U.S. Army force structure for this purpose would, in the steady state, cost about $5 billion a year in operations and sustainment costs (in 2025 dollars), once bases were built and equipment acquired. With luck and good diplomacy, many of those initial costs might be covered by local allies. Average annual costs for equipment could add another $2 billion to the total, given typical DOD ratios between procurement budgets and operations and support budgets.

Altogether, assuming that we actually added these forces to the standing U.S. military (rather than trying to maintain additional commitments with existing capabilities and units), the average annual costs of the new force posture would total by my estimates around $20 billion a year. Initial costs would be somewhat higher, perhaps $25 billion a year, as equipment was purchased, but longer-term costs would average out in this range. The defense budget would, in other words, have to be about $20 billion to $25 billion higher, each and every year, relative to what it would otherwise have been, to fund this set of force packages and military capabilities.

Could some of these added costs be offset by reforms and efficiencies in how DOD does business? Can the Department of Government Efficiency make a meaningful difference here? The answer is yes—but only to an extent. Finding savings in the Pentagon’s budget is difficult because the fat is marbled onto the muscle, so to speak. Also, waste is sometimes in the mind of the beholder (as with my proposals to hold intelligence funding flat and cancel certain redundant weapons systems). On top of that, restructuring organizations (or bases) often costs money in the short term, even if it can save money in the long term. As such, I estimate that reforms can reduce the annual defense budget by $10 billion, but not more (as discussed further in my 2023 paper, “How to be a ‘cheap hawk’ in the 2020s”). That is real money but less than what is needed in defense budget increases today:

• Conduct a sixth round of base closures ($3 billion to $5 billion).
• Retire platforms DOD wants to divest ($3 billion to $5 billion).
• Hold Intelligence Community real spending flat ($2 billion to $5 billion).
• Adopt performance-based logistics more widely ($1 billion to $5 billion).
• Cancel the new long-range cruise missile as well as the construction of a second plutonium pit production facility at Savannah River, South Carolina ($4 billion).
• Streamline hypersonic missile programs ($1 billion to $2 billion).
• Convert 80,000 uniformed positions to civilian positions ($3 billion).
• Use Title 12 and fixed-price contracts more in acquisitions ($1 billion to $5 billion).

Strategic nuclear forces and strategic/homeland defense

Nuclear and strategic force planning should also be rethought to include the interrelated issues of air and missile defense of the homeland.

To begin understanding this set of challenges, it is appropriate to note that the bilateral U.S.-Russia arms control framework that has simplified aspects of nuclear planning for decades is under serious strain and probably obsolete. Beyond the matter of Russia’s recent aggressiveness, history suggests that arms control in a multipolar strategic environment is complex, to say the least. With China apparently headed for an arsenal with 1,500 warheads, many of them long-range and modern in character, and Russia already in the range of 5,000—and the two countries acting in greater strategic collusion than at any time since the 1960s—does it suffice that the United States has nuclear parity with Russia while ignoring China’s capabilities? Before, the fact that France and the United Kingdom each brought a couple hundred warheads to the table for the Western alliance could be seen as balancing out whatever capability China possessed; that is no longer likely to be the case. Even if one is not particularly worried about target coverage at this point, given the huge numbers of nuclear weapons that still exist in the American arsenal, there is the matter of perception and a sense of global strategic momentum.

Faced with this situation, the United States could simply build up its nuclear forces. But Russia and China might reciprocate, leading to an arms race—and the United States is already modernizing its still-large nuclear force. The best response, therefore, may be asymmetric.

Thinking holistically about strategic stability and homeland defense, the United States might be wiser to consider deploying more capable defenses against possible missile or drone attacks. For example, with simple drone defenses and some deployment of systems based on THAAD and AEGIS/Standard Missile technologies, the United States could cover several of its major industrial/military sectors with modest, layered defenses against rogue, accidental, or coercive attacks or threats, as Robert Soofer and others have argued. (Recall that these capable defensive systems typically have ranges of hundreds of kilometers.) The goal would not be the unrealistic one of rendering adversarial nuclear forces impotent and obsolete but rather denying other countries coercive options and reasserting American technological advantages. The cost implications of doing this for several of the country’s key industrial and transportation regions, including major port and urban centers on both oceanic coasts in roughly a half dozen distinct regions, could cost $5 billion to $10 billion a year (reasoning by analogy with the defense concept proposed above for the Middle East). Some of this might be funded by forgoing nuclear modernization efforts that I have argued elsewhere to be unnecessary, most notably the fielding of a new long-range cruise missile as well as the construction of a plutonium pit factory at the Savannah River, South Carolina, site of the National Nuclear Security Administration.

Homeland defense should not stop with air and missile defense, however. The United States also needs to harden key military and civilian infrastructure, including transportation and communications networks as well as electricity grids and water systems, against cyber or kinetic attacks. This infrastructure is needed to keep Americans alive at home, to keep the economy working, and to deploy and sustain American military power abroad.

We know these systems are vulnerable; Beijing has already introduced malware into many of them through its Volt Typhoon group, with an apparent eye toward compromising their functioning in the event of war over Taiwan. In the United States, the private sector controls most such infrastructure; cybersecurity and safety requirements for the private sector are often not rigorous or binding. The government needs to toughen standards, share expertise and best practices, and possibly offer subsidies to companies to harden this infrastructure in the years to come. Most of this will not involve the national defense budget, however.

Other steps could well involve the defense budget. In particular, it would be prudent for state national guards to do some planning and some limited training regarding how they might provide site defense of a classic, kinetic variety for crucial infrastructure such as major bridges and tunnels, electricity transformers, major chemical and nuclear plants, and ports and airfields. Some of this can pick up where post-9/11 planning against a possible terrorist threat left off, but it should be updated for concerns about threats posed by state actors. It is difficult to be precise about annual costs, and over time some elements of national infrastructure may need to be built to more robust standards at greater expense. But an initial estimate of DOD costs would likely range into the hundreds of millions of dollars a year—enough money for some serious studies and preliminary training exercises, if not a wholesale remaking of the National Guard force structure.

Strengthening the defense industrial base

One more central element of America’s defense strategy in the new era of great-power rivalry concerns the U.S. defense industrial base. Since the COVID outbreak of 2020 and the all-out Russian attack on Ukraine of 2022, problems with the defense supply chain—indeed, supply chains of many types—have been recognized as acute national vulnerabilities. This is especially concerning when China, now the world’s top manufacturer, plays a disproportionately important role in producing many components and commodities that are needed in military systems (as well as in critical national infrastructure, in medicines, and in other goods without which many American lives could soon be in jeopardy). Gone is the insouciance with which defense officials, at the famous “last supper” of the early 1990s and on other occasions, used to tell the American defense industry essentially to take care of itself.

Injections of cash into some parts of the defense industrial base like submarine-building shipyards, to shore up subcontractor supply lines and improve surge capacity, have begun. But much remains to be done.

There are several possible ways to tackle this problem. They include establishing larger stockpile requirements for key munitions and building up inventory to those requirements, then sustaining them; establishing multiyear procurement buys to give industry greater incentives to beef up production capacity; promoting the building of adaptive manufacturing sites that can build non-military goods during periods of relative peace and switch over to military production when needed; and directly subsidizing contractors as well as subcontractors to build bare-bones production facilities that can be quickly made operational. Training and sustaining workforces are crucial, as well.

How much would a serious effort at strengthening and expanding the defense industrial base cost? One reference point is that Australia, under the terms of its AUKUS framework to build submarines with the United Kingdom and the United States, has pledged $3 billion to the United States and the U.K. for just this one sector of U.S. shipbuilding. Submarine production typically represents 3% to 5% percent of total DOD procurement, in dollar terms, so extrapolating to cover the whole U.S. defense industrial base could imply a need for $50 billion or more (over a multiyear period), if other sectors are comparably beleaguered. Actually, the $3 billion is only a down payment on what the U.S. and U.K. submarine shipyards likely need; DOD is devoting funds to the same purpose as well at this point. But since some other sectors may be in better shape, the extrapolation may still provide a reasonable ballpark figure on balance. That leads to an estimate of annual costs in the range of $10 billion if the goal is to address the problem aggressively over the rest of the 2020s.

A second reference point, admittedly a partial one but in this case focused on munitions, would be to ensure that the United States does not deplete its stockpiles and magazines in the event of war. A fascinating analysis of medium-range strike missiles by Mark Gunzinger concluded that some $30 billion in investment would be needed to have adequate inventories for a future great-power war, based on a need to fight for weeks at a minimum and not just days. (Again, one way to strengthen the industrial base is simply to buy more of certain key things, and then sustain those larger inventories.) If that were pursued over a five-year period, the average annual cost would be $6 billion—though just for a single category of munitions.

Indeed, DOD started to do some of these things during the Biden presidency. Its requested funding levels for 2025, for example, totaled about $75 billion for all industrial-base-related efforts, including $40 billion for near-term programs designed to strengthen the defense industrial base and enlarge inventories of key munitions. However, these large numbers are hard to understand. They likely include funding for many programs that were already underway. The good news is that the Pentagon does appear to be injecting serious resources into targeted interventions in the industrial base, even if the means by which it measures the additions and the methodologies by which it determines whom and what to subsidize remain works in progress.

Still, it is likely that up to another $10 billion in annual funding could be needed, in light of all the above, to make major headway in dealing with the interrelated challenges of increasing weapons and munitions stockpiles and production surge capacities.

China, Taiwan, and 2027: Accelerating deterrence improvements in the Western Pacific

There is no pressing reason to think China will attack Taiwan by 2027. Xi has only asked his military to strive to have the capability to seize it by then, a much different proposition than actually deciding to attempt it. Nor is it clear that requesting such a capability will easily turn into the creation of such. Crossing the Taiwan Strait with a big amphibious operation remains a daunting task, especially in light of enduring (if possibly slipping) American advantages in anti-submarine and undersea warfare and in stealth bombers. But deterrence can and should still be strengthened further beyond the steps that Biden has already taken.

The Pentagon has a way to go in carrying out transformation. Ideas like those that RAND scholar David Ochmanek has been promoting for years—including the use of uncrewed aircraft and submarines in the Western Pacific that could threaten Chinese ships trying to cross the Taiwan Strait without requiring long runways or big aircraft carriers to do so—have been slow to see the light of day. Drone technology and various types of robotic swarms, controlled by advanced algorithms including artificial intelligence, can also contribute to this and other defense requirements at costs in the low billions over a several-year period.

Robotics are not enough, however. The United States needs a more resilient basing network in the Indo-Pacific; the sites it has recently established in the Philippines, for example, have only very limited infrastructure and capacity associated with them to date. As Robert Blackwill and Richard Fontaine wrote, sizing up recent developments in their 2024 book, “In the end, then—more than a decade after the 2011 announcement of a U.S. pivot to Asia—little meaningful shift of military resources to the Indo-Pacific had taken place.” Because large bases can cost $2 billion to $4 billion to construct, given the need for bunkers, underground fuel, munitions storage, hardened shelters, repair facilities, and the like, the United States should plan on spending up to $20 billion or more over the next half-decade on an expanded network of bases in the Western Pacific region—above and beyond what it has already been spending with its Pacific Defense Initiative. Expediting this effort, and that of procurement of drones and related technologies for the deterrence mission regarding Taiwan, imply an average annual cost of $10 billion to $15 billion through the rest of the decade and beyond.

Keep developing “integrated deterrence”

Yet there may be a problem with all the emphasis on the Taiwan invasion scenario in U.S. defense planning toward China. To be sure, as noted above, that scenario must be addressed. But, given its all-or-nothing nature, it would seem to represent a cosmic roll of the dice for Beijing that the People’s Republic of China’s leaders may elect to avoid if at all possible. The United States and Taiwan (and Japan and possibly other allies) should double down on efforts to deter it—but not consider this scenario the most concerning and certainly not the most likely. Crossing the Strait requires the PLA to protect big, vulnerable ships and airplanes. By contrast, using various gray-zone methods of harassment against shipping, limited missile strikes against ships and ports, or submarine attacks as part of a blockade (whether airtight or “leaky”) seems more consistent with Chinese military thinking—and more promising in light of the current balance of military technologies. Were China to attempt a robust blockade of Taiwan with its submarine fleet, I have argued that the United States with Japan and Taiwan would have considerable difficulty reopening safe shipping and air lanes into Taiwan. China might even win such an engagement.

Military tools are crucial for deterring such contingencies, to be sure. But Trump was right in his first term to see economics as a crucial arena of national security strategy as well, including for deterring attacks through the threat of severe economic punishment (even if it would also hurt the United States badly). During the Biden administration, Austin was right to call for integrated deterrence—a concept I also championed in a 2019 book—and those efforts must continue so that the United States and its allies can use their economic power as well as their collective military might against Beijing in any future conflict. This effort will always be a work in progress, but much of it involves mitigating single points of failure and vulnerability in goods that are crucial to the functioning of the American economy as well as the survival of American citizens.

One case in point, though it may seem a surprising place to wind down a paper on military strategy: America’s dependence on China for many life-saving medications risks a cutoff in times of crisis that could put millions of American lives on the line. It should be reduced in the years ahead.

Conclusion

The world of the 2020s is indeed under considerable geostrategic stress. It is imposing more and more demanding burdens on the United States and its defense strategies and military forces all the time. That is not an argument for fatalism; many of the problems seem manageable, especially with the kinds of deterrent tools that have been developed since the end of World War II. It is important to remember the central success of American grand strategy and defense strategy since 1945 in preventing World War III by preserving the great-power peace. The United States generally succeeds in dissuading other countries from attacking its core interests once it clearly indicates where those interests lie and demonstrates the resolve as well as the capacity to defend them. But it will all take work, and resources, in the years ahead.