An old but far from forgotten sight is returning to Latin America: presidents facing TV cameras, addressing the nation in a moment of crisis — flanked by their generals.

In Ecuador, military leaders stood at attention behind President Lenín Moreno as he announced a state of emergency. A few days later, Chile’s president, Sebastián Piñera, did the same with a dozen camouflage-wearing officers at his side.

Both countries, reeling from the kinds of protests sweeping much of the world, also deployed troops to the streets — a jarring step in a region that has worked hard to put its history of military dictatorships behind it.

But presidential evocations of the military have extended, in recent days, beyond countries hit by anti-establishment unrest, suggesting there is more at play here.