cross the Rubicon

present singular third person crosses the Rubicon · participle present crossing the Rubicon · participle past crossed the Rubicon · past crossed the Rubicon

1. idiomaticTo make an irreversible decision or to take an action with consequences.

   He knew that by coming out to his family he would be crossing the Rubicon, but he could not live a lie anymore.

   5 more examples

   Britain will cross a “legal and ethical Rubicon” if parliament votes to permit terminally ill patients to end their lives, said the archbishop of Canterbury, Justin Welby, as leaders of all the UK’s major faith groups call on MPs to reject plans to allow assisted suicide.

   2015 September 5, Toby Helm, quoting Justin Welby, “Welby urges MPs: reject right-to-die bill that ‘crosses the Rubicon’”, in The Observer, →ISSN

   Having crossed the Rubicon, we can't go back. The impact of this transition is underlined by the fact that, despite our long evolutionary history as foragers, we generally can't survive by hunting and gathering when we have been stripped of that relevant culturally acquired know-how.

   2016, Joseph Henrich, chapter 17, in The Secret of Our Success […] , Princeton: Princeton University Press, →ISBN

   Will China cross the Rubicon by sending its military to Hong Kong?[…] As the world contemplates whether Beijing will cross the Rubicon and use military force to quell protests in Hong Kong, one question naturally comes to mind: Would the existing garrison be used, or would tanks and soldiers, recently seen moving toward the border in nearby Shenzhen, come across from the mainland? Would they conceivably act as a combined force?

   2019 August 16, Bonnie Girard, “Battle-Ready: The PLA’s Hong Kong Garrison”, in The Diplomat, archived from the original on 16 Aug 2019

   With the invasion of Ukraine the Russian president, Vladimir Putin, has thrown himself into the unthinkable. He has crossed the Rubicon into a time of war. He has no way back.

   2022 March 9, Luuk van Middelaar, “History is brutally back, and Ukraine will test Europe’s appetite for the consequences”, in The Guardian, →ISSN

   When the inevitable moment arrives to cross the romantic Rubicon in “Ticket to Paradise,” the machinery of the screenplay and the far-fetched nature of the moment don’t matter — they can just look at each other and sell it.

   2022 October 21, Jason Bailey, “How George Clooney and Julia Roberts Quietly Became the Tracy-Hepburn of Our Time”, in The New York Times