Without warning on Saturday, Gaza’s militant Hamas rulers attacked Israel by air, land and sea. Millions of Israelis in the country’s south awoke to the searing sound of incoming rockets. Air raid sirens wailed as far north as Tel Aviv. Israel’s antimissile interceptors thundered in Jerusalem. In an unprecedented escalation, armed Hamas fighters crossed into Israeli communities along the Gaza frontier, terrorizing residents and trading fire with Israeli soldiers. Israeli Prime Minister Benjamin Netanyahu and his far-right allies were scrambling to respond to the rapidly changing events as the death toll in Israel and Gaza continued to climb. Here are some key takeaways from the multi-pronged attack that has suddenly plunged Israel into war.