Nuclear Deterrence and U.S. Missile Defense

America's outdated nuclear deterrence policy is hindering the country's missile defense program, constraining it to a "limited missile defense" strategy. Consequently, essential missile defense initiatives are overshadowed by competing security priorities, gradual improvements, and insufficient funding, leaving the United States vulnerable to advancing conventional and nuclear missile threats. By adhering to inadequate defense strategies and outdated deterrence doctrines, America is impairing its capacity to develop and deploy effective missile defense systems, putting the homeland at risk from escalating modern threats.

The diversity of nuclear-capable nations compounds the challenge of nuclear deterrence. How do lesser nuclear powers like France, Great Britain, or China—nations that typically lack the global reach or extinction-level arsenals of the United States or Russia—fit into the equation? Even more troubling are countries like Pakistan, India, Iran, and North Korea, which present destabilizing influences and heightened risks of regional conflict.

The limitations of strategic frameworks like the 1968 Non-Proliferation Treaty (NPT) further complicate matters. While the treaty includes five nuclear signatories, nations like India, Pakistan, and North Korea remain outside its framework, intensifying regional tensions and increasing the risk of a nuclear exchange.

Further complicating the issue, non-NPT (Non-Proliferation Treaty) members continue to expand their nuclear arsenals and enhance their launch capabilities. According to the Stockholm International Peace Research Institute's 2024 report, Pakistan now possesses over 170 nuclear warheads. Similarly, India is modernizing its nuclear arsenal, with at least five new weapon systems currently under development. These advancements underscore the critical urgency of addressing the growing threats posed by these developments.

Experts have developed concepts like “minimum credible deterrence,” which focuses on maintaining a limited but adequate retaliatory capacity to address nuclear deterrence among regional powers. This doctrine is often coupled with a “no first use” policy, which pledges not to use nuclear weapons unless first attacked. However, the United States and NATO rejected this policy, maintaining a pre-emptive strike option to counterbalance Russia's overwhelming conventional capabilities.

The differences in global military strategies led to an arms race that peaked in the 1980s when there were over 40,000 nuclear warheads worldwide. Since then, “arms reduction” efforts have decreased this number to 12,121 today. However, new nuclear powers such as India, Pakistan, and North Korea have emerged, contributing to regional tensions. Additionally, regional antagonizers like Iran continue to pursue nuclear capabilities. The proliferation of nuclear weapons and deterrent derivatives has only heightened the risk of global conflict, underscoring the limitations of MAD as a long-term deterrent.

Years of nuclear arms reduction agreements and adherence to a nuclear deterrence doctrine have left America’s missile defense program constrained by a “limited missile defense” strategy. This outdated approach has relied on decades-old missiles, sensors, and kill vehicles. A Heritage Foundation 2020 analysis observed, "Instead of dampening an arms race, the ABM [arms reduction treaty] merely served to restrict the development of a robust U.S. missile defense.” This has left America’s Ground-Based Midcourse Defense (GMD) system—the nation’s primary defense against intercontinental ballistic missiles (ICBMs)—woefully inadequate.

The GMD system’s primary weapon, the Ground-Based Interceptor (GBI), consists of a boost and kill vehicle. Currently, 40 GBIs are deployed at Ft. Greely, Alaska, and four at Vandenberg Space Force Base, California. While the first Trump administration requested 20 additional GBIs, the program was canceled in 2019. Efforts to upgrade the system, such as the Redesigned Kill Vehicle (RKV), were similarly abandoned, delaying essential improvements. The 2022 National Defense Strategy (NDS) reaffirmed this by acknowledging that the GMD is “neither intended nor capable of defeating the missile capabilities of Russia and China.”

This led to the Biden administration’s plans to “meet this commitment by fielding 20 of the in-development Next-Generation Interceptors (NGIs) alongside the older GBIs, placing the first beginning in 2028.” However, unlike the RKV program, the NGI program will also involve developing a new booster or upgrading the current booster, which has not been addressed in any recent DoD budget submissions.

Global adversaries like China and Russia are rapidly advancing their missile capabilities, posing significant challenges to U.S. defense systems. China has deployed 75–100 intercontinental ballistic missiles (ICBMs), including multi-warhead versions, and developed advanced hypersonic glide vehicles that could outpace current U.S. missile defenses. The 2022 National Defense Strategy (NDS) highlights, “The PRC [People’s Republic of China] has dramatically advanced its development of conventional and nuclear-armed ballistic and hypersonic missile technology and capabilities…”

Likewise, Russia continues modernizing its intercontinental missile systems while developing precision-strike technologies aimed at overwhelming American defenses. The 2022 NDS notes, “Over the last 10 years, Russia has prioritized modernization of its intercontinental range missile systems and is developing, testing, and deploying new, diversified capabilities that pose new challenges to missile warning and defense of the U.S. homeland.” These advancements underscore the urgent need for a comprehensive, modernized missile defense strategy.

Despite escalating threats, the U.S. relies on outdated systems and incremental upgrades. Congressional priorities and funding allocations remain insufficient to field robust missile defense systems. For instance, the fiscal year (FY) 2025 Defense Budget allocates $28.4 billion—just 3% of its $850 billion total—to enhance U.S. missile defense capabilities. This funding level has remained unchanged since 2019. Furthermore, initiatives like the 2025 National Defense Authorization Act fail to mandate significant advancements in missile defense, highlighting a lack of prioritization.

In 1983, President Reagan’s Strategic Defense Initiative (SDI) proposed a comprehensive missile defense shield to make nuclear weapons obsolete. Reagan’s vision highlighted the dangers of relying on enemy rationality for national defense. While the SDI was ultimately unrealized, its principles remain relevant today. Reagan was a security realist and recognized that dependence on an enemy for one’s defense was unwise and left the world forever teetering on an Armageddon event. As Vince Houghton, historian/curator at the International Spy Museum in Washington D.C, states, “Reagan seemed to truly believe that the ballistic missile defense could finally release us from the perpetual, enduring, soul-crushing threat of Armageddon.”

President Trump acknowledges the significance of Reagan’s philosophy. In his first term, during the release of the 2019 Missile Defense Review, he stated, “Our goal is simple: to ensure that we can detect and destroy any missile launched against the United States, anywhere, anytime, anyplace.”

He has strengthened this strategy with a recent executive order directing the Department of Defense to develop an "Iron Dome Missile Defense Shield," or a next-generation missile defense system for the United States, to defend “against ballistic missiles, hypersonic threats, advanced cruise missiles, and other evolving aerial dangers.”

To achieve this, the United States must, in the short term,

In the long term,

Relying on outdated nuclear deterrence doctrines is insufficient to address the evolving threats posed by advanced missile technologies and the proliferation of nuclear weapons among rogue states and emerging powers. While deterrence has historically prevented large-scale nuclear conflicts, it has not stopped regional wars, dangerous arms races, or the growing risk of localized nuclear events that threaten global stability.

To ensure the safety of the American homeland, the U.S. must prioritize developing and deploying a comprehensive, modern missile defense system. By moving beyond the limitations of deterrence and adopting a forward-looking defense strategy, the United States can better protect its citizens, secure its national interests, and maintain its position as a global leader in security and technological innovation.

Major General Don McGregor (USAF ret.) is a combat veteran and an F-16 fighter pilot. While serving as a General Officer in the Pentagon, he was the National Guard Director of Strategy, Policy, Plans, and International Affairs, advising a four-star Joint Chiefs of Staff member. He was the lead liaison between the Council of Governors and the Secretary of Defense and administered the Department of Defense’s premier international affairs program, with over 80 global partnerships. He has held various operational command and director positions across the National Guard and military commands. Major General McGregor is an expert in defense strategy, policy, planning, and global security and is well-regarded for his expertise in the use of military forces to support federal agencies. He holds a master’s degree in Diplomacy and International Conflict Resolution from Norwich University.