In a lively routine, Monitor photographers and editors sift options each morning for the Viewfinder images that you see at the bottom of your Daily. It’s about balancing subject and geography with an eye to the day’s mix. About adding energy, or adding calm. Ideally, it awakens thought. On Thursday, one option showed U.S. soldiers on a morning run on the National Mall in Washington. These were the fresh young faces of an institution turning 250 years old this weekend. Other soldiers, from the National Guard, might deploy in the U.S. this weekend in dark, heavy gear. They’ll balance duty and a promise of safety – to one another, to civilians. On their morning jog in Washington these troops looked like the Los Angeles runners in today’s Viewfinder: sons and daughters, in T-shirts and shorts, thinking of a future.