In a rare public display of discord, Ukraine and its Western backers are at odds over who launched the missile that killed two Polish civilians.

It may be the most significant rift between Ukraine and its supporters, including the United States, thus far in the war, and it comes at a crucial time as winter approaches and Russian forces retreat.

Although the United States and its allies have termed the incident a regrettable accident, the starkly divergent interpretations of what transpired threaten to undermine the united front that has helped Kyiv maintain a strong military and diplomatic support from the West throughout the nearly nine-month-long conflict.

Ukrainian President Volodymyr Zelenskyy insisted that "it was not our missile" that hit Polish farmland, a terrifying incident that raised the specter of NATO and its nuclear-armed members being drawn directly into the Kremlin's war.

Wednesday on national television, Zelenskyy stated that the Ukrainian military leadership had briefed him personally on the matter, adding, "I have no reason to doubt them."

When asked early Thursday about the Ukrainian leader's assertion, however, President Joe Biden provided a striking rebuttal.

Biden stated as he returned to the White House from an overseas trip, "That's not the evidence."

An untimely dispute?

Less than twenty-four hours after the attack, NATO and Poland stated that it was likely a Ukrainian-launched air defense missile, intended to shoot down one of up to one hundred cruise missiles Russia launched against Ukrainian cities in what may have been the bloodiest barrage of the conflict to date.

Allow me to be clear. NATO Secretary-General Jens Stoltenberg told reporters at the alliance's headquarters in Brussels: "This is not Ukraine's fault." He added, about Ukraine's need for self-defense, "Russia bears ultimate responsibility."

The White House swiftly concurred, stating that the United States had "seen nothing that contradicts" Poland's assessment that a Ukrainian air defense missile landed on its territory. Defense Secretary Lloyd Austin stated at the Pentagon that the U.S. was "still gathering information" but agreed that the missile likely originated in Ukraine.

Austin stated, "We have full confidence in the Polish government's investigation into this explosion." And at the United Nations, U.S. Ambassador Linda Thomas-Greenfield attempted to refocus the conversation by telling the Security Council, "This tragedy would never have occurred if Russia had not invaded Ukraine without cause."

Former top Pentagon official for Russia Evelyn Farkas expressed concern to NBC News that the public disagreement was a distraction at a crucial time when the focus should be on rallying behind Ukraine and discouraging Moscow from invading any NATO territory.

The executive director of the McCain Institute for International Leadership, Farkas, stated that disagreements should be discussed behind closed doors. "Disputing publicly what type of missile it was only benefits Russia and gives the impression that we lack political cohesion and the will to stand up to Russia."

Throughout the war, Russia has attempted to sow discord between Ukraine and its allies to undermine Western support, which has been crucial to Kyiv's improbable military success.

Ukraine's supporters have also accused Russia of attempting to increase energy and other costs for European nations that rely on Russian supplies to increase public fatigue with the war and erode political support for sanctions against Russia and continued military aid to Ukraine.

Despite efforts by U.S. officials to downplay any disagreement, there were clear indications that Ukraine resented its allies' public stance. The tension stems from the fact that Kyiv has pushed back against Washington's suggestion that now might be a good time to negotiate with Russian President Vladimir Putin.

Moscow has attempted to take advantage of the divisions between Ukraine and its supporters.

In the fog of war, many Western officials initially speculated on Tuesday that the missile may have been launched by Russia, an assumption Kremlin spokesman Dmitry Peskov condemned as "another hysterical, rabid anti-Russian reaction that was not based on real data."

As U.S., Polish, and other intelligence and military officials began their investigations, the Biden administration initially deferred to Polish President Andrzej Duda and said little publicly. Ultimately, he concluded that the missile that struck his country was likely a "Russian-made" S-300, a surface-to-air missile from the Soviet era that both Russia and Ukraine possess.

After meeting urgently with G-7 and NATO leaders on the matter, Biden made his first public comments on Wednesday morning, stating that it was "unlikely, based on the trajectory, that it was fired from Russia," eliciting rare praise from the Kremlin.

"It is important to note the restrained and much more professional response of the American side and president," said Peskov.

And despite Poland's admission on Wednesday that the missile was likely Ukrainian, Russia summoned the Polish ambassador to the Foreign Ministry to be reprimanded, presumably because Poland had not pointed the finger at Ukraine sooner.

Maria Zakharova, a spokeswoman for the Russian Foreign Ministry, stated, "You were one step away from catastrophe only because [the Ukrainians] sucked you in with such a revolting tactic."

Secretary of State Antony Blinken spoke with Ukraine's top diplomat on Wednesday to "transmit information" about what the U.S. has learned about the strike, according to the State Department. The U.S. and its allies attempted to conceal any disunity that could play into Moscow's hands.

By Thursday, Kyiv's stance appeared to be softening.

Zelenskyy stated that a team of Ukrainian specialists will participate in the investigation of the blast site and suggested that only after the investigation can definitive conclusions be reached.

"I have no idea what happened. We cannot say for certain. In response to a question at the Bloomberg New Economy Forum, Zelenskyy stated, "The world does not know." "I am certain it was a Russian missile, and we fired from our air defense systems. However, it is impossible to discuss a particular topic at this time."

Andrew S. Weiss, a former White House and State Department official who is now with the Carnegie Endowment for International Peace, stated that Russia's previous attempts to drive a wedge between Ukraine and its Western allies failed and predicted that they will fail again.

"By their very nature, wars are highly dynamic, volatile, and unpredictable, and bad things do occur. This month, Weiss's book "Accidental Czar: The Life and Lies of Vladimir Putin" was released. This does not seem likely to become a significant source of contention.