New Delhi, May 2 -- The warnings to flee come suddenly: Texts pinging thousands of phones, automated calls from strange numbers, hard-to-read maps shared on social media by an Israeli military spokesperson.

Some maps cover broad swaths of Lebanon; others show specific buildings. Sometimes there is no warning at all before strikes, which have continued despite a nominal ceasefire between Israel and the Iran-backed Hezbollah militant group.

The warnings cause a rush to collect children and older relatives, and leave families with agonizing choices as they race for the blurry edges of the red-shaded maps. Entire villages have emptied, with over a million people fleeing at the height of the fighting. Unlike Israel, Lebanon has no air raid s...