With help from Eli Okun and Garrett Ross

HAMAS ATTACKS ISRAEL — Shocking and fast-moving news overnight, via Reuters: “Palestinian Islamist group Hamas launched the biggest attack on Israel in years on Saturday, killing at least 100 people and claiming it had taken dozens of hostages in a surprise assault combining gunmen crossing into Israel and a barrage of rockets fired from Gaza. …

“The Israeli military said it had responded with air strikes into Gaza, where witnesses reported hearing heavy explosions and multiple dead and wounded being carried into hospitals. The Israeli military said navy forces killed dozens of Palestinian militants trying to infiltrate Israel by sea.”

The stepback … “It is hard to describe just how unprecedented today’s developments are,” writes veteran BBC correspondent Paul Adams. “Not only is this likely to be the worst intelligence failure since the 1973 Yom Kippur war (and the timing is no accident — it’s 50 years almost to the day), but rarely, if ever, has Israel lost control of its own towns.”

What Israel is saying … “Citizens of Israel, we are at war. Not an operation, not a round [of fighting], at war,” PM BENJAMIN NETANYAHU said in a video statement, per Times of Israel. “I am initiating an extensive mobilization of the reserves to fight back on a scale and intensity that the enemy has so far not experienced. The enemy will pay an unprecedented price.”

What Hamas is saying … “This is not a [hit-and-run] operation; we started an all-out battle. We expect fighting to continue and the fighting front to expand. We have one prime target: our freedom and the freedom of our holy sites,” deputy chief SALEH AL-AROURI told Al Jazeera. He has also claimed that Hamas “has enough Israeli captives to make Israel free all Palestinian prisoners in its jails.”

What the administration is…