President Donald Trump’s desire to be a “peacemaker” will get its sternest test in Ukraine. He clearly believes there is a deal to be made to end the war. He is correct but the real challenge is not so much silencing the guns as keeping them quiet in a way that ensures Ukraine’s long-term security and survival. The good news is that it can be done.
Ceasefires are typically reached when both sides recognize they cannot achieve their wartime objectives through continued fighting, at least not immediately and at an acceptable cost. After nearly three years of war in Ukraine, which has cost hundreds of thousands of lives and wrecked the economies of both countries, that point is close at hand. Indeed, Ukraine and Russia have separately indicated their willingness to enter into peace negotiations. Ukrainian President Zelensky has even indicated he is prepared to defer discussion of the status of territories currently occupied by Russian forces to a later date along with the equally sensitive questions relating to war crimes and reparations.
Ukraine TOW Missile Attack. Image Credit: Creative Commons.
Therefore, it is not hard to imagine that both sides can agree to essentially freeze the conflict along a Line of Control—in the parlance of ceasefire negotiations—that approximates the current front lines.
For either side, acceptance of such an agreement will largely hinge on the assurances they receive about their future security. For Ukraine only the certain prospect of joining NATO and benefiting from its mutual security guarantees (or something comparable) to deter further Russian aggression will seemingly suffice. For Russia, only the certain prospect of Ukraine staying out of NATO would make a ceasefire palatable.
This seemingly irreconcilable conundrum is now more or less moot, however. The likelihood of Ukraine joining NATO was always slim and has receded further with the election of Donald Trump—never the greatest fan of costly new U.S. security commitments. The challenge now, therefore, is to convince Putin that Russia has nothing more to gain from continuing to fight while convincing Zelensky that Ukraine has nothing more to lose from ceasing to fight.
The first part of this equation entails demonstrating that the United States and its allies will only inflict more pain on Russia if it does not negotiate—through its support for Ukraine on the battlefield and through the imposition of ever more punitive sanctions.
President Trump has already said as much. The second part entails helping Ukraine develop and sustain formidable national defenses capable of credibly deterring Russian recidivism for many years, even decades, to come in lieu of formal NATO security guarantees.
To say the least this is a daunting task. Ukraine would need to defend a land perimeter with Russia and parts of Belarus that we estimate would be as much as 2000 kms in length. Its cities and critical infrastructure would likewise need to be protected from aerial bombardment as well as cyber interference and sabotage, while its vital maritime commercial routes through the Black Sea have to safeguarded.
But it can be done. Our calculations, based in large part on what Ukraine has achieved already on the battlefield, suggest that a total force of roughly 600,000 troops can defend an outer defense perimeter that would be fortified by dense minefields and others kinds of obstacles. Roughly one-quarter of this force would be conscripts deployed in peacetime with the remainder reservists that would be mobilized to fill out front-line positions if and when needed.
Since Ukraine’s outer defenses could still be breached, a mobile strategic reserve force made up of approximately 150,000 well-trained and equipped active-duty personnel would also need to be maintained to prevent any Russian breakthroughs—indeed of a decisive nature.
At the same time, Ukraine’s cities and critical infrastructure would be protected by a network of air and missile defenses with sufficient magazine depth such that it could resist many months of assault to buy time for further external replenishment. Cyber defense and site security would likewise be upgraded.
Finally, Ukraine should keep the very impressive, if modest, naval and air force capabilities it has been wielding in this fight. Adding in the needs for an “institutional army” to handle logistics, weapons acquisition, management, recruiting and training, our calculations point to a total force of just about one million uniformed personnel, again roughly half on active duty (with some of those conscripts, some professional volunteers) and the other half in a ready reserve.
Image of Russia President Putin. Image Credit: Russian Government.
Establishing and sustaining such a force will not be easy given Ukraine’s well-known demographic challenges, but it is not impossible. Over time, manpower requirements may even drop with the emergence of more labor saving military technologies.
Either way, Ukraine’s now-astronomical defense budget can be reduced to a more manageable size, for its own treasury and those of foreign donors—perhaps in the range of up to $40 billion a year in the steady state. This is not dissimilar to what Israel or South Korea now spend on their security.
Most of all, this kind of force would disabuse any rational (if evil) Russian planner of any hope for a quick and decisive victory in a future war.
About the Authors
Paul B. Stares holds the General John Vessey Chair at the Council on Foreign Relations, where he directs the Center on Preventive Action. Michael O’Hanlon holds the Phil Knight Chair in Defense and Strategy at the Brookings Institution.
