Ukrainian President Volodymyr Zelensky says that a deal to end the war with Russia is “90 percent ready,” with only 10 percent unresolved. That is good news for the new year, but Zelensky is not reassuring.

Neither is Russia’s President Vladimir Putin, or the self-styled peacemaker Donald Trump of the mighty USA.

This is because, as diplomatic experts love saying — reeking with pessimism while always hoping for the best — it is never the 90 percent that breaks peace, but the last sliver, the part that nobody wants to spell out.

Ukraine and Russia have been here before, and before them, warring nations across the ages. The war did not begin with tanks rolling into Kyiv in 2022.

Students of history will agree that it started in 2014, when Russia annexed Crimea and the world merely shrugged it off, papered over by the Minsk Agreement.

That document was solemnly signed, only to be ignored by the parties involved, although it may be conceded that it froze battle lines, if only temporarily. That is lesson one: agreements without enforcement are pauses, not peace.

Lesson two is geography. Russia occupies roughly a fifth of Ukraine and wants more. Moscow insists on “realities on the ground,” a phrase that sounds reasonable until you remember how those realities were created.

Kyiv, understandably, sees territorial concessions not as a compromise but as a receipt for future invasion. After Crimea came Donbas. After Donbas came everything else.

Putin has not been subtle about this, telling Russians that victory is inevitable, that talks are optional, and that force will finish what diplomacy does not.

Then there is the question Zelensky keeps circling about: guarantees. Ukraine has a long memory here. In 1994, it gave up nuclear weapons under the Budapest Memorandum, trusting assurances from great powers that its borders would be respected.

With the fall of Crimea and the gutting of Donbas, those assurances proved to be carefully worded condolences. Thus, when Zelensky insists on “strong security guarantees,” he is not being dramatic, but merely channeling the past.

Which brings us to the most uncomfortable part of the current optimism: the idea that the United States can promise Ukraine security for 15 years. Okay, even if Trump personally makes that pledge, the American system does not work that way.

A US president cannot bind his successor. He cannot lock Congress into funding. He cannot freeze public opinion. He cannot prevent the next election from rearranging priorities like furniture after a quake.

Likewise, Washington has walked away from long-term commitments before: Afghanistan, the Iran nuclear deal, even its own red lines. That is an unvarnished reality. American power is to be reckoned with, but it is also cyclical, partisan, and allergic to permanence.

From Kyiv’s vantage point, a 15-year guarantee from a four-year office is not a shield, but a leap of faith with a cliff at the end. Zelensky would be a fool to believe that. 

Finally, there is trust — or rather, the absence of it. Even as talks accelerate, Moscow signals escalation: claims of attacks, threats to harden positions, rhetoric about victory.

That is why the last 10 percent matters. It contains territory, enforcement, guarantees, credibility, and time. It contains the things that cannot be finessed with language or staged photo-ops.

Peace will come to Ukraine someday, but history suggests it will not come from a deal that relies on goodwill, assumes restraint, or trusts promises that outlive their makers.