The core mechanisms Sacks predicted for winter 2022–23 largely did not materialize.

1. Energy shortages and Putin’s leverage
   Europe certainly faced a serious energy price shock, but not the widespread physical shortages implied. EU gas storage was filled to ~95% before winter, a mild season plus demand reduction cut consumption sharply, and Europe got through winter without major blackouts or rationing of household heating.(iea.org) In parallel, the EU rapidly diversified away from Russian gas under the REPowerEU plan, with Russian pipeline supplies collapsing from about 155 bcm in 2021 to roughly 62 bcm in 2022 and 28 bcm in 2023, and Russian fossil fuels’ share of EU imports plunging thereafter.(en.wikipedia.org) By May 2023, the EU energy commissioner was publicly saying that Putin’s attempt to blackmail Europe with energy had failed, precisely because Europe had managed the winter and accelerated diversification.(energynow.ca) In other words, Russia lost long‑term leverage over Europe’s energy system rather than gaining it.

2. “Real fracture in the Western alliance”
   There were notable protests and political stresses over energy prices (e.g., large demonstrations in Prague against high bills and sanctions), which showed domestic discontent.(euronews.com) But at the level of governments and alliances, the predicted fracture did not occur. Through and after that winter, the EU and NATO continued to pass new sanctions packages, send increasingly heavy weapons, and admit or advance new members (Finland and then Sweden) – all signs of institutional cohesion, not breakdown. Survey work for the European Council on Foreign Relations in January 2023 found that, one year into the war and just after the first wartime winter, “cracks in the Western coalition have got smaller rather than larger,” with Europeans “surprisingly united” on supporting Ukraine and seeing the EU as as strong or stronger than before the invasion.(ecfr.eu) A separate analysis summarised this as the West regaining “unity and purpose,” noting that Europeans felt they had weathered the difficult winter and could sustain their stance against Russia.(voanews.com)

3. Overall assessment
   Winter 2022–23 did bring economic pain and some social unrest, but it did not significantly increase Putin’s leverage over Europe, and it did not cause the kind of visible, structural fracture in the Western alliance that Sacks predicted. If anything, that winter reinforced a strategic shift away from Russian energy and coincided with polling and policy evidence of continued or even strengthened Western unity on Ukraine. Taken against the specific claims in the quote, the prediction is best judged as wrong.