With an ugly war of attrition in Ukraine threatening to drag on for months, some fear possible escalation and suggest Washington should start talking to Moscow about a cease-fire and ending the war, or offer proposals to foster diplomatic opportunities.

Ending the fighting may well require talks, but the decision to negotiate should lie with Kyiv.

The Russian army launched a large-scale invasion of Ukraine on three fronts on February 24. However, by the end of March, it had to abandon its goal of capturing the Ukrainian capital and withdrew from much of northern Ukraine. The Kremlin said its forces would then focus on Donbas, consisting of Ukraine’s easternmost oblasts of Donetsk and Luhansk.

By mid-July, Russian soldiers had occupied most of Luhansk. That represented a symbolic victory, but in reality three months of grinding fighting gained little new territory. The Russian army, which has seen roughly 15,000 to 25,000 soldiers killed in action and lost much equipment, appears exhausted.

The Ukrainian military has also taken heavy losses but has been bolstered by flows of new arms from the West. Among other things, Russian war crimes have provoked sharp anger among Ukrainians and strengthened their resolve to resist.

Now hardly seems a propitious time for negotiations.

To begin with, Russian President Vladimir Putin and his Kremlin show no sign of readiness to talk seriously. Russian officials articulated their war aims for Ukraine early on: denazification (of a government headed by a Jewish president), demilitarization, neutrality, recognition of occupied Crimea as Russian territory, and recognition of Donetsk and Luhansk as independent so-called “people’s republics.”

In early July, Russian National Security Council Secretary Nikolai Patrushev restated basically the same goals. Foreign Minister Sergey Lavrov on July 20 said that Russia had broadened its military aims and would seek to seize territory beyond Donbas. He later added that Moscow sought to end the “unacceptable regime” in Kyiv.

The Kremlin’s goals remain unchanged — Ukraine’s almost total capitulation — despite the fact that Russia’s performance on the battlefield has fallen well short of expectations and could deteriorate as the Ukrainians take military actions such as systematically destroying Russian ammunition dumps. Do those who urge talks see space for any compromise that would not leave Ukraine in a substantially worse position than before the most recent invasion began in February?

Even a cease-fire presents peril for the Ukrainian side. It would leave Russian troops occupying large parts of eastern and southern Ukraine, with no guarantee they would leave. The Ukrainians have learned from bitter experience. Cease-fires agreed in September 2014 and February 2015, supposedly to end the fighting in Donbas, left Russian and Russian proxy forces in control of territory that they never relinquished and did not fully stop the shooting. Moreover, the Russian military might use a cease-fire to regroup, rearm, and launch new attacks on Ukraine.

This is not to say that a cease-fire or negotiation should be ruled out. But, given the risks inherent in either course for Ukraine, the decision to engage in talks on a cease-fire or broader negotiations should be left to President Volodymyr Zelenskyy and his government.

If Ukraine’s leadership were now to conclude that it should seek a settlement, Moscow’s unyielding negotiating demands would require that Kyiv consider concessions. They would be painful for the Ukrainian side and would almost certainly encounter stiff public opposition: A July poll showed that 84% of Ukrainians opposed any territorial concessions. That included 77% in Ukraine’s east and 82% in the south, the two areas where most fighting now occurs.

Any negotiation thus would be fraught with risk for Zelenskyy and his team. Only they can decide when — or if — it is time to talk. Battlefield developments and future military realities may affect the calculation in Kyiv. If Ukraine’s leaders choose to begin negotiations, the West should not hinder them, but the West also should not press them to negotiate before they see a net benefit in doing so. Western officials should be leery of opening any channel to Moscow that the Russians would seek to turn into a negotiation over the heads of the Ukrainians.

To be clear, this war has an aggressor, and it has a victim. Those who advocate that Washington talk to Moscow fear that, if the war continues, Russia might consider launching attacks on targets in North Atlantic Treaty Organization (NATO) member states. One should not wholly exclude that possibility, but the Russian military has its hands full with Ukraine. It likely does not want to take on NATO directly as well.

The United States and NATO certainly have a major interest in avoiding direct military conflict with Russia. However, in order to minimize that risk, is it right to ask the Ukrainian government to make concessions to the aggressor, concessions that could reduce the size and economic viability of the Ukrainian state, that would provoke a sharp domestic backlash in the country, and that might not end the Russian threat to Ukraine?

One last point to weigh. If the West pressed Kyiv to accept such an outcome, what lesson would Putin draw should his stated desire to “return” Russia’s historic lands extend beyond Ukraine?