India, April 10 -- Within hours of a fragile ceasefire between the United States and Iran, Israeli warplanes roared over Lebanon, unleashing one of the deadliest bombardments in the country in years, a military escalation that is now threatening to collapse the diplomatic breakthrough before it has even taken hold.

The scale and timing of the assault have jolted diplomats and analysts alike. More than 250 people were killed and over a thousand wounded in coordinated strikes across Beirut, the Bekaa Valley, and southern Lebanon, according to Lebanese officials, within hours of a fragile ceasefire. The attacks struck residential neighborhoods, medical facilities, and densely populated civilian areas, making it one of the deadliest bombard...