Yesterday, The New York Times reported that the administration of U.S. Pres. Joe Biden had belatedly granted Ukraine permission to fire American-made long-range rockets at targets in Russia.

“Missiles will speak for themselves,” Ukrainian Pres. Volodymyr Zelensky stated after the news broke.

Hours later under the cover of darkness, a Ukrainian battery fired eight of the 3,700-pound Army Tactical Missile System rockets at a Russian missile storage site in Karachev, in western Russia’s Bryansk Oblast 60 miles from the border with Ukraine.

It’s clear why the Ukrainians would target the 67th Main Missile and Artillery Directorate Arsenal in Bryansk. Spreading across at least 1.3 square miles, the arsenal is one of the Kremlin’s biggest ammunition storage sites. Ukrainian drones previously targeted the arsenal on Oct. 8.

It’s less clear how much damage the GPS- and inertially-guided ATACMS inflicted. The Russian Ministry of Foreign Affairs claimed air-defense batteries shot down five of the incoming rockets and damaged a sixth, whose “fragments fell in the technical zone of a military facility, causing a fire.”

According to Reuters, the Russians shot down just two of the missiles.

For around a year since donating the 190-mile-range ATACMS rockets, the White House had rejected Ukrainian requests to fire the rockets at targets on Russian soil. Instead, the Ukrainians fired the 1990s-vintage ATACMS—each of which can scatter nearly a thousand grenade-sized submunitions—at Russian airfields, supply depots and troop concentrations in Russian-occupied Ukraine.

The Biden administration finally changed its policy after North Korea sent thousands of troops to reinforce Russian troops conducting a costly—and so far unsuccessful—counteroffensive in Kursk Oblast, just east of Bryansk Oblast. A strong Ukrainian force occupies a 250-square-mile salient in Kursk. It seems Kyiv is determined to hold onto the salient as a possible bargaining chip in any future ceasefire negotiations.

The White House reportedly approved ATACMS strikes in support of Ukraine’s defensive efforts in Kursk, but continues to bar strikes elsewhere in Russia. The Bryansk arsenal undoubtedly stores munitions for the 50,000 Russian troops fighting in Kursk.

Russian Pres. Vladimir Putin recently lowered the official threshold for Russia’s first use of nuclear weapons, a move some observers have read as a response to the new ATACMS policy. Russian Foreign Minister Sergei Lavrov has absurdly described the international response to Russia’s February 2022 invasion of Ukraine as a “Western war against Russia.”

The Biden administration rejected that characterization. “We are not at war with Russia,” Deputy Pentagon Press Secretary Sabrina Singh said. “The party here that continues to escalate this war is Russia, by bringing in another foreign country into the battlefield.”

The Russians anticipated the change in ATACMS policy as early as a month ago—and began adding earthworks and other protective structures at their most vulnerable facilities in and around Kursk. “Evidence suggests Russia has been fortifying the Kursk military air base since early October,” noted Tatarigami, founder of the Ukrainian analysis group Frontelligence Insight.

If the Russians also fortified the 67th Main Missile and Artillery Directorate Arsenal in Bryansk, the preparations may have blunted the effects of the rockets, and their roughly 8,000 submunitions, that rained down on Tuesday.