Earlier this month, the House Armed Services Committee unanimously agreed to an amendment expressing support for deploying the Next Generation Interceptor (NGI) before the end of the decade. The NGI is intended to upgrade the nation’s homeland missile defense.

Consistent with longstanding policy from both Democratic and Republican administrations, the next-generation system would give our missile defenses the additional capacity and capabilities needed to keep ahead of growing ballistic missile threats from rogue states such as North Korea or Iran. The committee’s bipartisan support is reassuring in the face of calls to limit U.S. homeland defense.

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America’s limited intercontinental ballistic missile (ICBM) defenses are clearly designed to defend against rogue states with only modest nuclear-strike capacity. Our defenses would be quickly overwhelmed by adversaries with large numbers of nuclear-armed long-range missiles. Yet Russia and China claim that advancements to U.S. missile defense would negate their abilities to successfully retaliate against a U.S. first nuclear strike. Thus, they say, next-gen defenses would disrupt any concepts of assured retaliation, and harm stability among great powers.

Some advocacy groups have echoed this accusation. They want the U.S. to agree to Russia’s demand for missile defense limitations in a future arms control agreement. 

But as many in Congress recognize, NGI would make necessary upgrades to our defense against rogue threats without impacting strategic stability with peer competitors. 

For one, the administration plans to field only 20 NGIs to augment the current inventory of 44 ground-based interceptors. That deployment could not possibly defuse Russia’s arsenal of around 1,550 warheads deployed on hundreds of ground-, sea- and air-based platforms. Such is simple math.

Similarly, the notion that adding 20 more interceptors by the end of the decade is somehow driving Beijing’s strategic breakout is nonsensical. So is the idea that 64 interceptors could keep pace with the burgeoning Chinese missile threat, which is now expected to exceed Russia’s capabilities as China builds hundreds of new missile silos.

To change the strategic stability calculus with Russia and China would require much larger numbers of interceptors, which the United States has no plans to acquire.

But this modest 20-interceptor increase is necessary to outpace the rogue state threat and retain a measure of insurance against deterrence failure. Congress initially agreed to this increase to defend against North Korea’s growing ballistic missile arsenal and a potential future Iranian capability. It hedges against the real possibility that the U.S. inventory will fall behind these threats. 

But more important than this capacity boost are NGI’s capability upgrades. Compared to our current ground-based interceptors, which were fielded rapidly utilizing prototypes dating to the 1990s and repurposing other boosters, NGI will be specifically tailored to the missile defense mission.

For instance, NGI will carry multiple kill vehicles and advanced sensor and discrimination capability, meaning that a single NGI can more reliably defeat countermeasures or decoys, or potentially intercept multiple warheads.

Opponents may claim that the ability to intercept multiple warheads at once means the NGI can strike down a large number of incoming missiles. As a result, they say, NGI can affect a Russian or Chinese retaliatory strike, leading to that purported instability.

This claim is physically not true. The multiple-kill vehicle capability is needed to defeat multiple objects released from a single missile, not to defeat several missiles simultaneously. 

As North Korea improves its capabilities to add multiple warheads and decoys to its ballistic missiles, an interceptor with a single-kill vehicle may no longer suffice to defend against even one missile. 

Multiple-kill vehicles are therefore required to keep up with North Korean missile advancements. But as with its capacity increase, NGI’s multiple-kill vehicle capability could simply not match the decoys, penetration aids and multiple warheads carried by hundreds of Russian and Chinese missiles. 

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NGI will also have improved on-board sensor capabilities to detect and discriminate among incoming objects. As Deputy Secretary of Defense Kathleen Hicks testified before the Senate, advanced sensor and discrimination capabilities should take priority. Seeing the incoming threat is the first step to deterring attack—or if deterrence fails, denying the attack.

While the United States relies on nuclear deterrence to defend against Russia and China, it has long maintained the policy to maintain a missile defense system that outpaces the rogue state threat—and for good reason.

Missile defense can instill doubt in a rogue state that its plan will succeed. By removing the credibility of a homeland attack option, missile defense can prevent coercion or blackmail strategies used by rogue states to extract concessions from the U.S.

To continue to reap these benefits, the U.S. needs NGI to address the growing North Korean and potential Iranian threats. False accusations and claims about strategic stability should not interfere with the prudent and bipartisan pursuit of better defending the U.S.