DONETSK REGION, UKRAINE—I’m not as good a runner as I used to be. This came somewhere between the ninth and first floors of a murky, bomb-ravaged building at the edge of no-man’s land in the Donbas region of eastern Ukraine. I began scrambling downstairs after our sentinel yelled “Run!” I did not ask why, nor linger to consider how only minutes before we inched up these very same stairs, stepping carefully in each other’s footsteps to avoid setting off any booby-traps secreted to mutilate or murder anyone scouting this abandoned edifice. Children’s toys, full bottles of alcohol and other seemingly innocuous household items can be the disguised agents of your destruction, something I learned earlier at the Ukrainian Armed Forces Demining Centre in Kamyanets-Podilsky. No matter. I ran for my life. It was only after I got outside and turned a corner into comparative safety behind the building that I was told a Russian tank had emerged from the distant rubble, manoeuvring to take a shot. We didn’t offer the enemy a chance for target practice.