Israel did launch a full-scale ground invasion of Gaza on 27 October 2023, and that invasion is still formally ongoing more than two years later, with the campaign described in reference works as an "Israeli invasion of the Gaza Strip" running from 27 October 2023 to the present. (en.wikipedia.org) Large-scale ground and urban operations continued well beyond the initial months, including major offensives and sieges in Gaza City through January 2025 and in Khan Yunis, Beit Hanoun, and Deir al-Balah into mid–late 2025, contradicting the idea that the operation would be “not a long one.” (en.wikipedia.org)

A durable, structured ceasefire was only reached in stages starting with a temporary January–March 2025 armistice, which then collapsed when Israel resumed large-scale bombardment and ground attacks in March 2025; a more comprehensive ceasefire and withdrawal framework was not agreed until October 2025. (en.wikipedia.org) By then, the war had already caused tens of thousands of Palestinian deaths and massive destruction in Gaza, with major hostilities lasting roughly two years, far from the short campaign envisioned. (theguardian.com)

Moreover, the conflict produced substantial regional escalation before any lasting ceasefire: Iran carried out a large drone and missile strike directly against Israel in April 2024, and Yemen’s Houthi movement waged an extended campaign against international shipping in the Red Sea explicitly tied to the Gaza war, prompting US‑, UK‑, and EU‑led naval responses. (en.wikipedia.org) While this fell short of a classic multi‑front conventional “regional war,” it clearly contradicted the prediction that a brief operation would end in a ceasefire before the situation escalated in the region.

Because the Gaza ground campaign turned into a prolonged, years‑long war with only late and fragile ceasefires, and significant regional spillover occurred before those ceasefires, Sacks’s scenario of a short operation capped by an early, stabilizing ceasefire did not materialize.