The U.S. Department of Defense loves a good buzz phrase: capability over capacity, making the tough choices, taking risk now to reduce future risk. The DoD has used all three to rationalize a fiscal 2022 budget that shrinks the U.S. military’s size in the hope that new technologies will eventually lead to new acquisitions. The truth is the proposed budget is the latest in a series of funding requests that have fallen short of what the DoD needs to rebuild for the future.

The result of 30 years of “building down to build up” is a military that lacks the capacity to fight a single peer aggressor plus defend the U.S. homeland and deter nuclear attacks. Since defense leaders seem reluctant to be forthright and sound the alarm, Congress must step in.

Take the case of the Air Force. According to the 2018 National Defense Strategy, defeating a peer adversary’s invasion of a U.S. ally or friend is the most stressing requirement for sizing our military. Preventing a Chinese seizure of Taiwan or a Russian invasion of the Baltic states will require U.S. forces that can launch large-scale precision strikes and otherwise go on the offensive within hours. Only air power — bombers, fifth-generation fighters and other air combat systems — can respond over global ranges in time to do this.

Yet, 66 percent of the Air Force’s bombers have been sent to the boneyard since the Cold War, and its fighter force is less than half the size of the force that defeated Iraq’s military in 1991. For context, the Air Force’s 140 B-1s, B-2s and B-52s — its smallest bomber force ever — may be able to generate 30 strike sorties per day. B-52 bombers alone flew an average of 50 sorties per day during Operation Desert Storm.

The lack of an immediate, overwhelming response to such an invasion would have a devastating impact on the United States. Failing to prevent China from seizing Taiwan or completing its dominance over the South China Sea would risk demoting the United States to a second-tier military power in the Western Pacific. Similarly, a successful Russian invasion of the Baltics could fracture NATO — a long-term goal of President Vladimir Putin’s regime.

Surprisingly, the seeds for defeat lie in the same document that shifted the DoD toward planning for great power conflict. The 2018 NDS prioritizes sizing the U.S. military to prevent China or Russia from seizing territory along each of their peripheries they aspire to control. It also assumes that defeating such an invasion will lead to peace, which means preparing for a prolonged conflict is a lesser priority. But what happens if China or Russia instead chooses to continue the fight and run out the clock on a U.S. military that has sized its forces, munitions inventories and other capabilities for a short war?

The 2018 NDS also abandoned a long-standing requirement to size the U.S. military to fight a second opportunistic aggressor. As the DoD reported to Congress in 1993, a two-war force was critical to preventing “a potential aggressor in one region to be tempted to take advantage if we are already engaged in halting aggression in another.” This logic is as sound today as it was in 1993, a fact noted by the congressionally appointed National Defense Strategy Commission.

The “capability over capacity” argument for cutting U.S. forces may have made sense in the past, but not in an era where China and Russia’s combined defense spending now exceeds the DoD’s budget. Planning for one war — and a short one at that — presents China and Russia with a viable path to victory. Both are aware of the U.S. military’s diminished size and the fact that its attrition reserves are mostly intended to compensate for losses that occur during training and day-to-day operations, not in a high-intensity conflict.

Denying China and Russia a path to victory will require the DoD to revisit its planning assumptions and increase forces and capabilities that best enable U.S. commanders to quickly blunt an invasion. More long-range stealth bombers and fifth-generation fighters, larger inventories of precision-guided missiles (including anti-ship weapons), and unmanned aircraft should be at the top of this list.

The good news is the DoD has an opportunity to do this as it updates its National Defense Strategy and develops budgets to support it. Unfortunately, the outlook for increasing the size of its forces is not optimistic. Chairman of the Joint Chiefs of Staff Gen. Mark Milley has said he is comfortable with a flat defense budget, which is really a budget in decline after accounting for inflation.

This directly contradicts a recommendation by the National Defense Strategy Commission — which included Dr. Kathleen Hicks, now the deputy secretary of defense — that 3-5 percent budget growth was needed to begin closing the DoD’s strategy resource gap. Several U.S. service chiefs have also declined to endorse real growth in defense spending during recent appearances on Capitol Hill.

If America’s senior military leaders are not willing to advocate for resources they know are needed, then Congress must. The alternative is to continue the cycle of cuts that diminish America’s military and increase risk that China or Russia can prevail in a war with the United States.

Retired U.S. Air Force Col. Mark Gunzinger is the director for future concepts and capability assessments at the Mitchell Institute for Aerospace Studies. He previously served as deputy assistant secretary of defense for forces transformation and resources within the policy office of the Office of the Secretary of Defense.

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