Not since Yom Kippur in 1973 has the Middle East been so close to all out war.
That conflict, also known as the Ramadan War, raged for 19 days between Israel and a coalition of Arab states led by Egypt and Syria. It claimed up to 20,000 lives, including some 2,500 Israeli soldiers. Many thousands more on both sides were maimed and injured.
It is a reminder of what is at stake today after the biggest exchange of fire on the Israel-Lebanon border.
Exactly what happened in the early hours of Sunday morning remains obscured by the fog of war and the desperate need for both sides to establish deterrence through strength – real and perceived.
Israel says it moved first and pre-emptively after detecting Iranian-backed Hezbollah was poised to launch a major strike in revenge for the assassination of Fuad Shukr, one of its most senior commanders, in Beirut on July 31.