The US Navy has fielded a low-yield, submarine-launched ballistic missile warhead. The move was met with skepticism from some strategists and outright condemnation from anti-nuclear advocates. But the concerns are overwrought; the move is smart and is an appropriate response to what US adversaries are doing.

The Trump administration’s Nuclear Posture Review, the nuclear strategy document that nests with the National Security and Defense Strategies, calls for “a small number of existing submarine-launched ballistic missile (SLBM) warheads” to provide a comparatively low-yield option. The US objective is to “help ensure that potential adversaries perceive no possible advantage in limited nuclear escalation, making nuclear employment less likely.” Put another way, US adversaries—in particular, Russia—have lowered the threshold at which they might consider employing a nuclear weapon, and America is responding.

If the United States only has high-yield nuclear options to respond to a Russian low-yield first strike in, for example, a purely conventional conflict with a NATO member, Russia may believe the US would not respond with its own nuclear attack but instead sue for peace. If Russia truly believes this, Moscow could think employing such a weapon is to its advantage. Indeed, the types of nuclear weapons the Russians continue investing in, combined with their military doctrine, have led US officials and military leaders to believe Russian strategy purportedly seeks to “escalate to deescalate.” By adding this low-yield option, America seeks to provide a calibrated option in the event the Kremlin thinks launching a low-yield nuclear attack makes sense. It strains credulity in this scenario that the United States would respond by launching high-yield weapons that would target and destroy Russian strategic weapons, cause untold loss of life, and almost certainly escalate the war dramatically. In contrast, the tailored approach with more low-yield options is more moral and therefore more in line with US sensibilities. These new options increase America’s credibility in the mind of adversaries, thus raising the nuclear threshold and decreasing the chances of Russia initiating an attack.

But this might not convince the biggest skeptics because the United States already possesses low-yield options that aircraft can deliver. But those options will not be able to provide the prompt response SLBMs offer and will have trouble getting through Russian air defenses. When it comes to nuclear weapons, it’s better to have a spectrum of options to offer a tailored response in a variety of complex scenarios. Doing so causes the adversary to doubt his plan’s wisdom, complicate his calculations, and deter him from the initial act of aggression.

Another concern opponents have is that Russians won’t be able to tell if a high-yield or low-yield SLBM is incoming in the event the United States does employ the weapon. But this concern, while not easily dismissed given the stakes, does not outweigh the benefits of fielding it. Recall the scenario that the United States would plausibly employ the weapon—in response to a Russian attack of low-yield nuclear weapons. The Russians, knowing the US fielded this low-yield option, would surely not have such uncertainty about the incoming SLBM’s yield. But if they launched a massive strategic attack, they would guarantee an overwhelming American response, effectively ending the current Russian state. After all, in this scenario, they wish to avoid the total destruction of their nuclear forces. They should have the sense to not be so presumptuous, especially when they would be considering the events they initiated that elicited the response.

The bottom line is US nuclear weapons are a force for peace and stability. The better the United States can convince our adversaries that there are credible options available that make their acts of aggression simply not worth the cost, the more effectively the United States can deter large-scale war and preserve peace. The Trump administration’s latest moves seek to do just that.