New Delhi, Aug. 5 -- WASHINGTON - Donna Powell was taking shelter under a shade tree in Columbia Heights last Saturday when two soldiers in camouflage passed without a word, their rifles slung low in the August heat. "They're everywhere," she said, watching them round the corner toward the park. "They're just hiding wherever it's shady."

Powell's observation has now acquired a price tag. A cost estimate from the Pentagon, released Monday by Senator Elizabeth Warren of Massachusetts, puts the expense of Donald Trump's ongoing National Guard deployment in the nation's capital at roughly $1.4 billion through January 2029, a commitment covering three years of sustained military presence with no sign of a drawdown date.

As of late July, 4,60...