Can Trump end war in Ukraine?

OPINION:

On the campaign trail, President-elect Donald Trump promised more than once to end the war in Ukraine in one day. He even said that if elected, he would have “it settled before I even become president.”

Mr. Trump said: “I would tell Zelenskyy, no more [presumably weapons]. You got to make a deal. I would tell Putin, if you don’t make a deal, we’re going to give him a lot [presumably weapons]. We’re going to [give Ukraine] more than they ever got if we have to.”

Clearly, Mr. Trump’s threat to provide no more weapons to Ukraine is a powerful incentive for Ukrainian President Volodymyr Zelenskyy to come to the negotiating table. At a minimum, stopping the flow of U.S. weapons would significantly degrade Ukraine’s ability to defend itself. In the most extreme case, it could mean Ukraine’s defeat.

On the other hand, Mr. Zelenskyy would welcome more weapons, though it’s not clear how powerful an incentive that would be for Russian President Vladimir Putin to negotiate. This is because it wouldn’t necessarily guarantee Ukraine could win — that is, expel Russian forces.

Moreover, the amount of military aid the United States can continue to provide Ukraine is limited by how willing and able it is to draw down its inventory of weapons (which must be balanced against the readiness of U.S. forces) and the ability of the U.S. defense industrial base to produce sufficient weapons to meet demand.

But even if the U.S. can give Ukraine more weapons, simply providing hardware that its military could not use effectively or repair easily is hardly a recipe for defeating Russian forces. And in what is currently a war of attrition, there is also the question of how many troops Ukraine would have to use those weapons.

Providing more weapons is also not without risk. For example, when the outgoing Biden administration gave Ukraine a long-range Army Tactical Missile System, or ATACMS, and authorized Ukrainians to use it to strike targets in Russia, Mr. Putin updated Russia’s nuclear doctrine and fired a nuclear-capable ballistic missile at Ukraine.

At some point, Russia may no longer view U.S. support for Ukraine as a proxy war — especially if the United States provides weapons that are striking targets in Russia. It is also reckless to assume a threshold wouldn’t be crossed that could trigger a nuclear response — particularly if Mr. Putin is backed into a corner.

These realities will constrain Mr. Trump’s ability to make good on his promise. But if Mr. Trump could broker a deal — even if it takes more than a day — what would such a deal look like?

Ukraine’s preference would be to return to the status quo and restore its prewar borders. But that would be akin to the Soviet withdrawal from Afghanistan in 1989 and likely viewed as a defeat in Mr. Putin’s eyes. What could Mr. Trump offer to persuade Mr. Putin to swallow such a bitter pill and save face politically?

Before the war, Russia made several security demands, including not admitting Ukraine (and other former Eastern Bloc countries) into NATO. These demands were originally rejected but may have to be revisited and seriously considered as bargaining chips. One possible outcome to ponder is a geographically restored neutral Ukraine without any prospects of joining NATO. This would certainly test whether Russia’s prewar security demands were earnest.

Russia has said it wants to retain territory in Ukraine already occupied by its forces. Ukraine has rejected such proposals, and many in the West would be reluctant to accept this because it would be seen as giving Mr. Putin a victory, and many do not trust that Mr. Putin would not attempt further expansion into Ukraine at a later date. According to Mr. Zelenskyy, “It’s the same thing Hitler did, when he said ‘give me a part of Czechoslovakia and it’ll end here.’”

What could Mr. Trump propose to alleviate this concern? As an extreme possibility, Mr. Putin might have to acquiesce to Ukraine joining NATO in exchange for Russia gaining territory. Even if NATO didn’t admit Ukraine, a fortified border and Ukrainian military heavily armed with Western weapons to defend against Russia is a prospect Mr. Putin might have to accept as a quid pro quo.

These are certainly not all the possible outcomes. Ultimately, if Mr. Trump is to follow through, he’ll need to decide what a Ukraine-Russia deal would look like. This is at least as important — if not more important — than admonishing Mr. Zelenskyy and Mr. Putin that they need to make a deal.

• Charles V. Peña is a nonresident fellow at Defense Priorities. He has more than 30 years of experience as a policy and program analyst and senior manager, supporting both the departments of Defense and Homeland Security. He is the former director of defense policy studies at the Cato Institute and author of “Winning the Un-war: A New Strategy for the War on Terrorism.”