Daniel M. Gerstein works at the nonprofit, nonpartisan RAND Corporation and is an adjunct professor at American University. He was the undersecretary (acting) and deputy undersecretary in the Science and Technology Directorate of the Department of Homeland Security from 2011-2014 and the principal director for counter weapons of mass destruction in the Office of the Secretary of Defense (Policy) from 2009-2011. The views expressed are his own.

(CNN) President Trump traveled to the Pentagon on Thursday to discuss the National Defense Strategy, an unclassified version of which will be released Friday. Undoubtedly, key topics of discussion on the new strategy included the proliferation of nuclear weapons and missile technology, and the need for the protection of space assets essential to providing early warning in the event of a nuclear attack.

Over the next couple of weeks, the Nuclear Posture Review will be released. Taken together, these documents will shape the US nuclear defense policy over the course of the administration and likely usher in significant changes. One of those changes could come on the question of low-yield nuclear weapons, or those weapons most likely to employed on the battlefield. These weapons are smaller, less destructive and have shorter ranges than strategic nuclear weapons -- though the death and destruction they cause could still mean substantial casualties.

Recent reports indicate possible US and Russian expansion of nonstrategic nuclear weapons' capabilities, or those weapons developed for battlefield military uses. The Wall Street Journal reported that the Pentagon is planning new nuclear weapons, including a "low yield" warhead, with a view to countering Russia and China.

For the US, such actions would represent a major change in policy , while for Russia, it would mean a continuation of ongoing force modernization, doctrinal changes and military exercises that regularly feature nuclear weapons such as limited-use options for warfighting and escalation control.

The Nuclear Posture Review -- like those issued by the three previous administrations -- will likely reaffirm the necessity of ensuring the US deterrence remains viable and the capability to develop and field nuclear warheads. However, the return of tactical nuclear weapons to the US arsenal for the first time since the end of the Cold War would be a significant change.

From the Cold War to today, Russia has maintained strategic and nonstrategic nuclear weapons. The only category of nuclear-capable forces that neither the U.S. nor Russia have maintained were the Intermediate-Range Nuclear Forces (INF) -- with ranges of 500 km to 5,500 km -- that were eliminated as part of the 1987 INF Treaty. However, the Russians have recently developed a ground-launched cruise missile that the US believes violates the INF Treaty.

Experts make compelling cases for developing low-yield nuclear weapons on both sides of the argument. Yet, judging the costs and benefits of such a policy reversal comes down to a matter of perspective and largely depends on where one begins in approaching the question, whether from a warfighting, deterrence or nonproliferation perspective.

From the perspective of warfighting, reintroduction of nonstrategic nuclear weapons provides another powerful tool to the arsenal. Lower yields provide a nuclear capability that is more likely to be incorporated into a conflict. Certain missions -- striking deeply buried targets like command bunkers -- call for nuclear weapons to increase the probability of destruction of these targets.

Naysayers make the case that the conventional arsenals of both nations are more than adequate to attack complex targets with a reasonable surety of destruction. During the Cold War, lower-yield weapons provided a measure of deterrence by linking the battlefield and strategic nuclear capabilities and providing an offset to the perceived Soviet advantage in conventional forces in Europe. Ominously, the Russians have already begun to incorporate these systems into their warfighting plans , something the US halted following the Cold War.

Nuclear weapons provide unique opportunities for deterrence, perhaps discouraging an adversary's action due to the fear of the consequences and the potential escalation that could raise the stakes of conflict.

The theory has been that two nuclear nations had to exercise greater caution before entering into a conflict, as controlling escalation or blundering into a strategic nuclear engagement was always a possibility.

With the reintroduction of these weapons, a nation could use them to escalate the conflict, demonstrate a willingness to continue to escalate, and seek to cause the adversary to terminate the conflict on less favorable conditions (the Russian doctrine of "escalate to de-escalate"). However, it is also possible the use of these weapons could be misinterpreted and result in escalation to a strategic nuclear exchange, with potentially devastating consequences

If one approaches the policy change from a nonproliferation perspective, the outcomes are uniformly negative. Incorporating tactical nuclear weapons into America's military planning would undermine 65 years of nonproliferation that goes back to President Eisenhower's 1953 "Atoms for Peace" speech , which sought to share the benefits of atomic power while containing the risks, and the 1970 Nuclear Nonproliferation Treaty for preventing the spread of nuclear weapons and associated technologies.

Ultimately, the goal has been to lessen the likelihood that nuclear weapons will continue to proliferate to other nations. Despite these efforts, nine nations today have nuclear weapons -- the US, Russia, United Kingdom, France, China, India, Pakistan, Israel and North Korea. Others such as Japan and South Korea have demonstrated mastery of the technical components of a nuclear weapons program, but have not developed such weapons. Still others such as Syria and Iran have been "dissuaded" from developing these weapons.

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Developing low-yield nuclear weapons, establishing a doctrine for their use and incorporating them into military exercises sends a dangerous signal that nuclear warfighting is just one more capability in the toolkit.

The cases of Pakistan and North Korea demonstrate how fragile these nonproliferation regimes can be. The recent rapid enhancements to the North Korean nuclear and missile program provides ample evidence of how challenging it is to prevent global proliferation.

Heated rhetoric about nuclear weapons use, modernization of stockpiles and changes to extended deterrence could undermine nonproliferation programs. Heading "back to the future" through the development of low-yield nuclear weapons could make nonproliferation goals more difficult to achieve. At the same time, it could signal a new willingness to consider these weapons as part of a spectrum of warfighting capabilities, rather than as a necessary component of the US deterrence posture.