To counter China in a potential Indo-Pacific conflict scenario, the U.S. Air Force (USAF) would need to field at least 200 B-21 stealth bombers and 300 sixth-generation F-47 fighters, according to a recent report by the Mitchell Institute for Aerospace Studies of the Air & Space Forces Association (AFA). The study argues that these capabilities would be critical to denying China sanctuaries from which it could launch air and missile attacks, particularly in the context of a possible invasion of Taiwan. This recommendation would represent a significant expansion compared to the Pentagon’s current acquisition plans.
The report, titled “Strategic Attack: Preserving the Air Force’s Ability to Deny Enemy Sanctuaries,” was authored by Heather Penney and retired Colonel Mark A. Gunzinger. In the document, the authors argue that the combination of B-21 bombers and F-47 fighters would allow penetration of adversary airspace and operations “from the inside out,” striking bases and other critical infrastructure within mainland China. This approach is intended to sustain prolonged deep-strike operations, rather than limited, episodic incursions.
Currently, the U.S. Air Force has stated its intention to procure “at least” 100 B-21 bombers and 185 F-47 fighters. According to the Mitchell Institute’s analysis, these numbers would be sufficient for isolated, high-intensity missions, such as the so-called Operation Midnight Hammer, which included strikes against Iranian nuclear facilities led by B-2 bombers and F-35 fighters. However, the authors warn that these force levels would be insufficient to sustain a prolonged air campaign against a peer adversary.
In this regard, Penney stated during a briefing that the currently planned fleet represents “a raiding force, not a campaign force.” As a result, the report recommends doubling the B-21 procurement to at least 200 aircraft and increasing the F-47 fleet by nearly two-thirds, reaching approximately 300 fighters. According to the authors, this combination would provide a dedicated enemy sanctuary-denial capability.
“The F-47 operating alongside the B-21 and other aircraft within the Air Force’s long-range strike family can form the Department of War’s sanctuary-denial force,” Penney and Gunzinger wrote. This structure would be designed to ensure the ability to strike strategic targets in depth and sustain operational effort throughout a prolonged conflict. The proposal also highlights the need to maintain sufficient reserves to absorb attrition over time.
While such an expansion of these fleets could take a decade or more to materialize, the authors recommend that no B-2 bombers be retired from active service in the meantime. They also suggest increasing F-35 procurements to bolster penetration capabilities in the short and medium term. These interim measures are intended to mitigate current force limitations while next-generation platforms are developed.
The report further places these recommendations within a long-term trend, noting that the U.S. Air Force’s bomber and fighter inventory has steadily declined since the end of the Cold War. As currently conceived, the B-21 and F-47 programs are primarily aimed at replacing aging platforms such as the B-1 and the F-22, rather than increasing overall force capacity. According to Penney, this situation stems from budgetary constraints rather than operational requirements.
Compounding this issue, part of the fleet must be held in reserve for nuclear deterrence missions and the defense of the U.S. homeland, further reducing the number of aircraft available for long-range strike operations. “Two hundred B-21s are not based on a World War III scenario, but on calculating how many are needed when accounting for reserves and the credibility required to deny sanctuaries and strike key centers of gravity in China, while also maintaining an attrition margin to sustain a prolonged conflict,” Penney explained.
One of the report’s central themes is its critique of the current balance of Air Force capabilities, which the authors believe is overly tilted toward stand-off attack systems. These include hypersonic missiles and complex long-range sensor and communications networks designed to strike targets without aircraft entering enemy airspace. While this approach seeks to reduce risk to aircrews, the report argues that it is insufficient on its own.
Penney and Gunzinger warn that the current combat force remains heavily reliant on legacy bombers and fighters lacking advanced stealth capabilities. “If not modernized with sufficient quantities of next-generation stealth aircraft, this legacy force would have to close thousands of long-range kill chains for hundreds of hours in a peer conflict—well beyond the current and projected capacity of the Air Force,” the authors wrote. From this perspective, stand-in platforms capable of operating inside adversary airspace are deemed indispensable.
The report also addresses the economic dimension of these decisions, acknowledging that acquiring an additional 100 B-21 bombers and 115 F-47 fighters would entail upfront costs exceeding $100 billion. Nevertheless, Penney noted that stand-off capabilities are not inexpensive either, particularly in a conflict that could require striking hundreds or thousands of targets. By way of example, the U.S. Army’s Dark Eagle long-range hypersonic weapon reportedly costs more than $40 million per shot.
Finally, the authors emphasize that long-range kill chains are technically complex and vulnerable to disruption or attack by an adversary. In contrast, bombers offer greater intercontinental range and significantly larger payloads, expanding the range of operational options available to military planners. The analysis concludes that a balanced mix of stand-in and stand-off capabilities would be decisive in sustaining U.S. airpower projection against China.
In parallel with these recommendations, both industry and the U.S. Air Force are already showing signs of progress in both programs. In late January 2026, Northrop Grumman reported that it is working with the Air Force to expand production of the B-21 Raider stealth bomber, with the expectation of finalizing a new contract before the end of March. According to CEO Kathy Warden, “we continue to work closely with the Air Force on plans to increase the program’s production rate (…) I’m optimistic and believe we’ll reach an agreement this quarter.”
Meanwhile, in November 2025, U.S. Air Force Chief of Staff General David Allvin stated that the service expects the first flight of the sixth-generation F-47 fighter to take place in 2028. This announcement falls under the Next Generation Air Dominance (NGAD) program, intended to replace the F-22 Raptor as the Air Force’s primary air superiority platform. Although the program remains highly classified, it has been indicated that the F-47 will feature a stealth design, the ability to operate alongside unmanned systems, and an approximate range of 1,800 kilometers, with an initial planned fleet of 185 aircraft.
While the cited report highlights the need to expand the U.S. air fleet to ensure total supremacy over Washington’s primary strategic rival—China—it is worth noting that, as of today, the United States still maintains greater strike and deployment capabilities than its Asian counterpart. For example, it operates a fleet of more than 500 F-35s across all variants (A, B, and C), making it the country with the largest number of fifth-generation stealth fighters in the world. In addition, in 2025 Lockheed Martin completed the delivery of 191 aircraft, surpassing the previous year’s total of 142 units, while Northrop Grumman has delivered 1,500 center fuselages for the production of new F-35 Lightning II stealth fighters.
Last but not least, the United States operates a fleet of 10 aircraft carriers (as the USS Nimitz is set to be decommissioned), all of them nuclear-powered. In addition, the next carrier, USS John F. Kennedy of the Gerald R. Ford class, has already begun its sea trials. This stands in stark contrast to China, which operates only three aircraft carriers, all conventionally powered and therefore requiring frequent refueling.
Images for illustrative purposes.
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