 In recent months, Ukraine has stepped up attacks on Russia's oil and gas facilities, in response to Russia's routine targeting of Ukrainian civilian energy infrastructure. Both sides insist they're striking legitimate military targets. Yet civilians have also come under repeat fire. The attacks prompted Russian President Vladimir Putin to launch a new offensive aimed at creating a buffer zone within Ukraine and the Biden administration to lift restrictions on Ukraine's use of American weapons to strike some military targets inside Russia proper. Charles Mainz, NPR News, Moscow.