Former service members and combat medics from other countries are in Ukraine to train civilians. They typically have just days with new conscripts before they are sent to the front.
Yevgeny Prigozhin, known as "Putin's Chef" because of his company's origins in the catering business, now fields a mercenary army of 50,000. Its role in Ukraine is central to Russia's war effort.
Russia and Ukraine are believed to have suffered equally horrific losses in the war. But when it comes to troop strength, the math is on Russia's side. Its population is four times Ukraine's.