Washington is currently absorbing the fallout from Ukraine’s blitz on Russia’s Kursk region, as the scale of President Zelensky’s bold gamble becomes clear.

U.S. officials are currently assessing how the move could change the political and military dynamics of the war and what implications it has for Washington’s long-wavering stance on how Ukraine can use U.S.-supplied weapons.

The surprise raid, which caught both Russian and apparently Western leaders by surprise, highlights one of the riskiest dilemmas for the Western-backed defense of Ukraine: President Biden has consistently sought to give Kyiv the power to push back the Russian invasion without risking an American escalation with Moscow. While President Putin has always sought to portray the conflict as a war between Russia and the West, Mr. Biden has sought to set clear limits on U.S. policy to debunk that narrative and prevent a conflagration.

But Ukraine’s attack on the Kursk – military analysts say it is the largest foreign invasion of Russia since World War II – raises a number of pressing questions for the White House. Will it rapidly expand the limits set by Washington on Ukraine’s use of American and NATO weapons systems? Is there a risk of crossing Russia’s red lines on Western involvement in the war? And if not, has President Zelensky shown Washington that he can see through Putin’s bluff?

Despite the risks and uncertainty, there is a kind of surprised admiration among some in Washington at Zelensky’s actions. Analysis of comments by US officials over the past week reveals something about the emerging position. The administration insists that Ukraine did not warn it in advance of the attack. White House spokeswoman Karine Jean-Pierre said Washington had “nothing to do with it”.

As for the use of American weapons, White House, Pentagon and State Department spokespeople have not officially confirmed whether they are being used. But given Ukraine’s reliance on American and NATO weapons systems, it seems overwhelmingly clear that this is the case. Vladislav Seleznev, a former spokesman for the General Staff of the Ukrainian Armed Forces, told Voice of America that the US-supplied HIMAR missile launchers were critical to the advance.

US approval of Ukraine’s use of its weapons in the attack on Kursk is certainly implicit. Pentagon spokesman Major General Patrick Ryder said this week: “We believe they are within the political boundaries that we have set. That policy has not changed, particularly with regard to the use of American weapons.” Officials say the attack is “consistent” with their policy “from the beginning” that Ukraine can defend itself against attacks across the border.

But Pentagon spokeswoman Sabrina Singh added: “We do not support long-range attacks on Russia. These are more like crossfire attacks. I will not give an exact range.”

The US is Ukraine’s largest arms supplier, making this relationship the most consequential for the country’s future prospects. Just last week, the Pentagon approved the 63rd shipment of equipment in three years, including Stinger missiles and artillery shells. But since the Russian invasion began, President Biden’s approach has been marked by his initial refusal to supply even more advanced weapons – including Himars missiles, Patriot missile defense systems and F-16 fighter jets – before later changing his mind.

The same goes for the White House’s policy on Ukrainian attacks on Russian territory. For many months, President Zelensky asked for permission to attack military targets in Russia that facilitate attacks on Ukraine. In May, Biden finally authorized the use of US weapons for attacks across the border into Russia, but only within a limited radius around the Kharkiv region – which was under Russian attack. The White House called Ukraine’s permitted actions “counter-strike” measures.

“Their use near the border is authorized when (Russian military sites) across the border are used to attack specific targets in Ukraine,” Biden said in June. “We do not authorize attacks 200 miles into Russia, and we do not authorize attacks on Moscow, on the Kremlin.”

A few weeks later, the same permission was extended to all points along the border where Russian forces were preparing an attack on Ukraine.

Since then, Zelensky, along with some European allies and some Democrats in Washington, has called on the US to “solve” Ukraine even more. Specifically, the Ukrainian president wants to be able to use ATACMS systems or long-range missiles supplied by the US to fire deep into Russia and take out drone or missile launch bases. Washington has rejected this.

All of these decisions are accompanied by the ominous warnings of President Putin, who had previously threatened to use “all available means” if Russia’s territorial integrity was threatened. Added to this is his nuclear sabre-rattling, when he sees the West as an intolerable threat to Russia through the Ukraine war.

Ultimately, President Biden’s position could be summed up as follows: Ukraine can decide how best to defend itself with American weapons, including attacks across the border, but within very clear limits – including not having long-range missiles. The words he used in June suggested that Ukraine’s borders were “near the border.”

The Kursk offensive takes America’s dilemma into unexpected territory — literally and figuratively. The Ukrainian incursion is a cross-border ground assault reportedly involving between 5,000 and 12,000 troops. Some unconfirmed Russian reports suggest that Ukraine’s troops may have penetrated as far as 30 kilometers into Russia. In the middle of this week, Kyiv declared that its troops controlled 1,000 square kilometers of Russian territory, including more than 70 villages and towns, and had captured hundreds of prisoners of war. Russian officials said some 132,000 people had been evacuated from their homes.

Since US officials are still reluctant to discuss the matter publicly in detail, I get the impression that they are still trying to figure out what this means for the situation on the battlefield and the future of the war, and what impact it has on Putin’s calculations.

If Zelensky was frustrated with what he felt was President Biden’s caution or slowness in making decisions on gun permits, he may have wanted to show him that he could force both him and Vladimir Putin to act. That’s a risky gamble.