Rescuers work at the site of the apartment building hit by a Russian drone during a Russian missile and drone strike, amid Russia’s attack on Ukraine, in Kyiv, Ukraine, Dec. 27, 2025. Photo: REUTERS/Viacheslav Ratynskyi

Four years ago, Russian armored columns pushed toward Kyiv, expecting a swift collapse of the Ukrainian state. That collapse never came.

Russia failed in its central objective. Kyiv did not fall. Ukraine’s government did not crumble. NATO did not fracture. What Vladimir Putin sought to prevent remains intact: a sovereign, Western-aligned Ukraine.

Russia today occupies roughly one-fifth of Ukraine’s territory, including Crimea and large swaths of the Donetsk, Luhansk, Zaporizhzhia, and Kherson regions. Much of that territory was seized either in 2014 or during the early months of the 2022 invasion. Since then, Moscow’s gains have been incremental and costly, measured in devastated villages rather than decisive breakthroughs.

Ukraine, despite facing a significant infantry shortage, continues to hold Russia to incremental gains while inflicting heavy casualties. The war has killed or wounded hundreds of thousands of soldiers and displaced millions of civilians. Cities such as Mariupol, Bakhmut, and Severodonetsk lie in ruins.

But the consequences of this war extend far beyond Ukraine’s borders. Europe has begun to rearm, addressing chronic underinvestment in defense since the end of the Cold War. As a result of the Russian invasion, Finland and Sweden joined NATO, doubling the alliance’s border with Russia, a strategic setback the Kremlin apparently didn’t anticipate. Energy markets have been reshaped as European states have largely weaned themselves off Russian oil and gas. Washington and its allies have been forced to rethink deterrence, force posture, and industrial capacity for sustained conflict.

In Ukraine, Putin faces a dilemma: he cannot impose the outcome he wants on the battlefield, yet he refuses to scale back his maximalist demands. So, the Kremlin has turned negotiations into another front in the war. Moscow has sought to use diplomacy to split the United States from Ukraine and Europe and enlist US help in forcing Kyiv to swallow Putin’s terms. The Kremlin demands that Ukraine cede the remainder of its eastern Donbas region, abandon its aspirations of joining NATO, accept limits on its military’s size and capabilities, and enshrine legal protections for Russian cultural influence. In short, Putin seeks to achieve through diplomacy what Russia has failed to secure decisively through force.

That approach only works if Moscow believes time is on its side. At present, the Kremlin appears to calculate that Western political divisions will deepen and that Russia can eventually exhaust Ukraine’s resistance. Until Putin’s calculus changes, diplomacy without leverage will not moderate Russian objectives. It will entrench them.

Shifting that calculation requires raising the cost of continued aggression and making Putin understand that neither Western will nor Ukrainian resistance will break. The United States retains significant tools to do so. Rather than slashing military assistance for Kyiv as the Trump administration has done, additional support can help Ukraine increase the price Russia pays for its battlefield advances. Strictly enforcing and building upon existing sanctions, particularly on the energy revenues that finance the war, can tighten economic pressure on the Kremlin.

Pressure, steadily applied, can shape negotiating behavior. Concessions offered prematurely are counterproductive. By leaning on Kyiv to bend to Moscow’s demands, Washington risks reinforcing Kremlin intransigence. And by rushing into negotiations without first establishing leverage, the Trump administration wasted valuable time.

Ending the war is a worthy objective. But the terms matter. A settlement that emboldens Russian revanchism or merely grants Moscow time to rearm for a follow-on war would damage US interests — with implications extending well beyond Ukraine. It would undermine the credibility of US security guarantees, destabilize Europe’s security architecture, and shift American strategic bandwidth away from higher-priority theaters.

Four years into this war, the lesson is not that diplomacy is futile. It is that diplomacy must be facilitated with strength. The United States still possesses the tools to create that leverage. Using them is not escalation. It’s smart negotiating.

Keti Korkiya is a research analyst in the Russia Program at the Foundation for Defense of Democracies (FDD).