What does Israel know about Iran’s retaliation window and is that why it prepared for a ‘long war’?

Israel said it launched pre‑emptive strikes on Iran on Feb 28 and soon after, Iran fired missiles toward northern and central Israel, triggering sirens across the country as the IDF said it detected launches and moved to intercept incoming threats. Israeli reporting suggested the government was preparing for several days of fighting, with emergency measures activated nationwide amid fears of wider escalation. Iranian media reported explosions in Tehran and other cities including Isfahan, Karaj and Kermanshah as the conflict rapidly intensified.