This week’s major Ukrainian attack on the Russian port of Sevastopol in Crimea was likely the largest strike on Russian naval targets since the war’s start.

Significantly, the UK’s Sky News has confirmed that British-supplied long range missiles were used in the overnight Sept. 12-13 attack which likely damaged a Russian submarine and warship. “A Ukrainian and a Western source said that British Storm Shadow cruise missiles were deployed,” Sky News reports.

Kremlin sources counted ten cruise missiles fired against the key Black Sea naval port, and claimed anti-air defenses downed seven of these. An additional attack by unmanned boats was thwarted too, a statement said.

Storm Shadow missiles were supplied to Ukraine after approval to supply these was announced earlier this year from London on May 11. The missiles have a range of 155 miles, making them among the longest range weapons in Ukraine’s arsenal, and are fired from aircraft.

The Sky report notes that while Kiev stopped short of confirming outright the type of missiles used, statements from officials strongly point in that direction: 

However, Lieutenant General Mykola Oleschuk, the head of the Ukrainian Air Force, posted an image on his Telegram channel of the burning shipyard, with the caption: “And while the occupiers are ‘storming’ and they are still recovering from the night cotton [Ukrainian slang for explosions] in Sevastopol, thank you to the pilots of the Air Force of the Armed Forces of Ukraine for their excellent combat work!”

Likely the projectiles were launched from Ukrainian aircraft. Such future attacks could be more devastating if and when Western partners hand over F-16 fighter jets, after training for Ukrainian pilots is complete.

Open source analysts have said the submarine damaged in the attack was at the dry dock and was the Black Sea Fleet’s Rostov-on-don Project 636.3 diesel submarine. A warship was also said to be damaged, likely the Minsk Project 775 Ropucha-class large landing ship.

Rybar Live: Missile strikes on Sevastopol, 13 September

Mikhail Zvinchuk, head of Russian think-tank Rybar: «The question remains open as to why one of the aircraft managed to launch an attack from the direction of Zmeiniy if Zmeiniy is within range of our air defence assets» pic.twitter.com/hLMr0ozuSz

— Rybar Force (@rybar_force) September 14, 2023

Currently, the Biden administration is mulling giving Ukraine the Pentagon’s long-range Army Tactical Missile Systems, or ATACMS, which is capable of hitting targets 190 miles away. Per ABC News:

“They are coming,” said one official who had access to security assistance plans. The official noted that, as always, such plans are subject to change until officially announced.

A second official said the missiles are “on the table” and likely to be included in an upcoming security assistance package, adding that a final decision has not been made. It could be months before Ukraine receives the missiles, according to the official.

However, when pressed this week, NSC spokesman John Kirby would not confirm that the decision has been made. There are some in the administration who’ve also expressed concern for escalation, given Kiev could more easily unleash devastating cruise missile attacks deep inside Russia with the ATACMS.