Ukraine's pleas for permission to fire long-range missiles in Russia have dominated high-level engagements between US and UK officials this week
However, despite a visit to Kyiv by the nations' top diplomats and a meeting between their leaders, no consensus has been reached.
British Prime Minister Keir Starmer met with US President Joe Biden in Washington on Friday and they discussed whether to allow Ukraine to strike deep in Russian territory using Western-supplied weapons, which already are in its possession but continue to be restricted by the White House.
At the centre of the talks was the Storm Shadow — a British-French missile that the UK supplied to Kyiv last year but has not been green-lit for use outside Ukrainian borders.
What are Storm Shadow missiles?
Storm Shadows are air-launched cruise missiles capable of hitting targets up to 250 kilometres away.
While Ukraine already has drones with much longer range (1,800km according to Ukraine's military intelligence chief Kyrylo Budanov), the missiles are designed for attacks against high-value targets such as hardened bunkers and ammunition stores.
Storm Shadows are low-flying missiles, making them harder to intercept than drones, and they can hit targets with precision.
Ukraine has pushed for months for the West to lift restrictions on their use inside Russia, thereby allowing it to pressure Moscow and gain an edge against the Kremlin's military forces on the front line.
Kyiv says long-range capabilities will help it counter glide-bomb attacks from Russian airfields, strike military command and control hubs, and target fuel and weapons depots.
Two European diplomats, speaking on condition of anonymity, told Reuters that Ukraine had submitted to the US and Britain a list of potential targets inside Russia that could be hit if allowed.
Why is Washington's permission needed?
It concerns the parties involved in the production of the missiles.
The Storm Shadows were supplied by the UK, but they were developed jointly with France, with Italy also involved in their manufacturing.
The missile's components are provided by the US, which means Washington may also have to approve changes to the conditions of their use.
In France, the identical missile is called SCALP, which Ukraine is also seeking to use.
Although Britain is expected to seek US approval before lifting its restrictions on Storm Shadows, a French diplomatic source said Paris did not need authorisation from Washington for Ukraine to use SCALPs.
Two US officials familiar with Friday's talks said they believed Mr Starmer was seeking Mr Biden's approval to allow Ukraine to use British Storm Shadows for expanded use in Russia.
The officials said they believed Mr Biden would be amenable.
US concerns
Britain became the first country to supply long-range missiles to Ukraine in May last year when it began sending the Storm Shadows, but a condition was that they only be used in counter-offensives within Ukrainian borders.
Kyiv's Western and European allies had so far refrained from easing this restriction over fears it would escalate the war.
For Mr Biden, the decision is not just tactical. It also raises questions about whether authorising such strikes might risk a direct war between NATO and Russia.
Another US concern is that focusing on long-range strikes downplays what could be a bigger immediate threat: Russia's advances on the ground inside Ukrainian territory toward the strategic city of Pokrovsk.
US officials believe the loss of the city would be a significant blow.
However, Ukraine's unexpected invasion of Russia's Kursk region has changed the dynamic, putting Moscow on the back foot and exhibiting strength in its offensive capabilities, prompting the West to rethink the use of weapons.
Despite no decision being made on the cross-border use of Storm Shadows in Friday's meeting, reports have suggested the US gave the go-ahead in private.
Ukrainian President Volodymyr Zelenskyy also wants more long-range weaponry from Washington, including the Army Tactical Missile System, known as ATACMS.
But Lieutenant Colonel Charlie Dietz, a Pentagon spokesperson, said ATACMS were not the answer to the threat Ukraine faced from long-range Russian glide bombs, which were being fired from more than 300km away, beyond the missile's reach.
American officials also do not believe they have enough of the weapon systems available to provide Ukraine with the number to make a substantive difference on the ground.
They also believe Kyiv should focus on halting a Russian advance in Ukraine's east.
Mr Biden, however, has hinted that a change could be afoot. In an exchange with reporters this week about whether he was ready to ease weapons restrictions on Ukraine, he responded: "We're working that out now."
Russia threatens war with NATO
Russia warned at the United Nations on Friday that allowing Ukraine to fire missiles far into Russia would turn NATO into "a direct party to hostilities against a nuclear power".
President Vladimir Putin threatened retaliation and accused the US and European nations of de-facto participation in the conflict.
He argues the flight missions for the West-supplied missile systems "can essentially only be input" by NATO military personnel, not Ukrainians, and any decision to allow Kyiv to use them means nothing less than NATO's direct involvement in the conflict.
White House spokesman John Kirby said on Friday the US took such threats seriously, but acknowledged there was nothing new in Mr Putin's rhetoric.
Democratic US Representative Jason Crow, a member of the House intelligence and foreign affairs committees, said Russian forces did not have the strength for a wider war.
"I don't believe there's any indication that Vladimir Putin has an interest in picking a fight with NATO," he told Reuters, pointing to Russia's massive losses of men and armour in Ukraine.
"To the contrary, I think he is avoiding a NATO confrontation."
"Vladimir Putin is not 10-feet tall. We have seen that repeatedly over the last couple of years. He's very vulnerable and, frankly, he's in a position of significant weakness."
Mr Zelenskyy's appeal has garnered support in US and European security and diplomatic circles, including from some former US generals and diplomats, politicians and security analysts.
They argue Russia's previous threats of escalation against the West have proven hollow and that US restrictions on weapons are making it impossible for Ukraine to gain the battlefield momentum it needs.
Asked what he thought about Mr Putin's threat, President Biden said: "I don't think much about Vladimir Putin."
ABC/wires
