Nearly 50 years to the day after the Yom Kippur War of 1973, Israel has again been taken by surprise by a sudden attack, a startling reminder that stability in the Middle East remains a bloody mirage.
Unlike the series of clashes with Palestinian forces in Gaza over the past three years, this appears to be a full-scale conflict mounted by Hamas and its allies, with rocket barrages and incursions into Israel proper, and with Israelis killed and captured.
The psychological impact on Israelis has been compared with the shock of 9/11 in America. So after the Israeli military repels the initial Palestinian attack, the question of what to do next will loom large. There are few good options for Prime Minister Benjamin Netanyahu, who has declared war and is being pressured into a major military response.