On Monday, The New York Times reported that U.S. President Joe Biden had approved the use of American-made long-range missiles by Ukraine to target Russian locations. Ukrainian President Volodymyr Zelensky quickly declared that the missiles would “speak for themselves.”

Shortly afterward, a Ukrainian artillery unit fired eight Army Tactical Missile System rockets—each weighing 3,700 pounds and carrying up to 1,000 grenade-powered submunitions—at a large Russian ammunition depot in Karachev, Bryansk Oblast, located about 60 miles north of the Russia-Ukraine border. The early-morning attack, which set the depot ablaze, marked the beginning of what could be a significant campaign of deep strikes targeting Russian forces and infrastructure in the Kursk Oblast area of western Russia.

In line with Biden’s decision, the governments of the UK and France also gave Ukraine the green light to use British and French munitions against Russia. On Wednesday morning, Ukrainian bombers reportedly launched 10 Storm Shadow cruise missiles at a target in Maryino, a town in Kursk, just 25 miles from the border.

While the exact target of the 2,900-pound missiles remains unclear, the large-scale nature of the attack suggests it was aimed at a high-value, likely fortified, target. The Storm Shadow missile, developed by the British company BAE Systems, is specifically designed to destroy hardened structures like underground bunkers, which explains its use when the Ukrainians targeted a Russian submarine in Crimea in September 2023.

According to one Russian blogger, the target was a command post where Russian and possibly North Korean officers were coordinating the assault on the Kursk salient. The strike on the command center, which killed officers and their staff, was described as a devastating blow to the enemy’s leadership.

The attack may have involved up to five Ukrainian Su-24 bombers, each carrying two precision-guided Storm Shadow missiles. The Ukrainian air force has modified many of its Su-24 aircraft to launch these advanced weapons, including the French-made SCALP-EG missiles, in addition to the Storm Shadows.

The primary mission of the Ukrainian air force’s 7th Tactical Aviation Brigade, based in western Ukraine, is now to launch these high-precision weapons, marking a shift from the earlier use of unguided bombs. While launching cruise missiles from a distance of 190 miles is safer than dropping bombs from above, it still involves significant risks, as Ukrainian pilots often have to contend with enemy missiles during their strikes.

Despite the dangers, these strikes are crucial. Ukraine has developed a variety of deep-strike weapons, including rockets, drones, and glide bombs, but few have the destructive power of the Storm Shadow, which is capable of penetrating and destroying fortified command bunkers.