Why No One Is Winning the Russia-Ukraine War After Four Years

Looking up above Ukraine's snaking front lines, some drones zip toward far-away targets while others hover lower— buzzing right above the heads of soldiers on the contact line, searching for their next target.

"There is constant activity in the air almost everywhere," says one Ukrainian soldier on the front line. He declined to provide his name or any details about where he's been deployed, as he was not authorized to speak...