Ukraine may have realized the first advantages of being permitted to launch attacks on Russian territory with Western weaponry. France and Germany granted approval for Ukraine to utilize their arms against Russian targets, following Russia's offensive against Kharkiv on May 10. US sources indicated that Ukraine was allowed to use US weapons for counter-fire purposes in Kharkiv. However, there were limitations on preemptive targeting of Russian weapons systems and troop concentrations. Ukraine launched its first declared strike on Russian territory using Western weapons by attacking the Kerch ferry crossing with ATACMS missiles. This action caused disruption to military logistics and damaged ferries in the Crimea region. Germany and the US imposed restrictions on weapon use similar to those of the US, focusing on defending attacks on Kharkiv from neighboring Russian territories. Ukraine expanded its strikes, targeting a Russian air defense complex in Belgorod using high mobility army rocket systems. The deployment of F-16s was also discussed by Ukraine's allies, with Denmark and the Netherlands indicating no restrictions on using the fighter jets. In contrast, Belgium refrained from allowing Ukraine to use Belgian F-16s to target Russia, reflecting differing positions among EU countries. As tensions escalated, Russian President Putin reiterated warnings on the potential use of nuclear force, while the US downplayed the significance of the change in restrictions. On the ground, Ukraine continued to send reinforcements to the Kharkiv front, with reports of casualties on both sides and significant destruction of Russian military assets by Ukrainian drones.