“Without the EU, the UK would likely have become politically integrated into the United States.”

The claim is a counterfactual assertion that, absent EU membership, the UK would likely have become politically integrated into the United States (the "51st State"). The cause is "absence of EU membership"; the effect is "UK political integration into the US." There is no evidence supporting this causal link, and the available evidence actively points against it: 1. **No historical movement toward US statehood.** The historical record contains only isolated, fringe proposals for the UK to join the US as a state — a 1947 suggestion by US Senator Richard Russell that was received "coldly" by the British, a disputed claim that Harold Wilson informally raised the idea with Lyndon Johnson in the 1960s (described by LSE historian Piers Ludlow as a "nice bit of whimsy" unlikely to be given serious thought), and parliamentary petitions attracting only a handful of signatures. None of these constituted a credible political trajectory toward integration. 2. **The US actively supported British EU membership.** According to CEPR and UCL historical analyses, the United States was a consistent supporter of European integration and specifically backed British accession to the EEC from the Marshall Plan era onward. US policy was to encourage Britain into Europe, not to absorb it as a state. 3. **The actual counterfactual was tested by Brexit and the opposite occurred.** After the UK left the EU in 2020, it did not move toward political integration with the US. It remained fully sovereign; a US-UK trade deal proved elusive; and analysts noted that on major international issues London was often closer to Brussels than Washington. Contemporary analyses describe "51st state" status as "fantasy," distinguishing economic/defense dependence from political union. 4. **Dependence is not integration.** Even sources critical of UK reliance on the US (on nuclear deterrence, cloud infrastructure, corporate ownership) describe economic and military dependency — not political incorporation into the US federal system. The UK retained its Crown, Parliament, currency, and independent foreign policy. The claim conflates cultural/economic Americanization and strategic dependence with formal political integration. The evidence indicates that EU membership was not a decisive factor preventing US statehood; rather, there is no plausible mechanism by which its absence would have produced that outcome. The real-world test of EU withdrawal confirmed that the UK did not become the "51st State." Sources: CEPR, "Why did Britain join the EU? A new insight from economic history," https://cepr.org/voxeu/columns/why-did-britain-join-eu-new-insight-economic-history; UCL Discovery, "Integrated Relationships: The Impact of European Integration on the Special Relationship, 1969-1973," https://discovery.ucl.ac.uk/id/eprint/1348313/; Wikipedia, "Accession of the United Kingdom to the European Communities," https://en.wikipedia.org/wiki/Accession_of_the_United_Kingdom_to_the_European_Communities; The Independent, "Wilson wanted UK to be US state," https://www.independent.co.uk/news/wilson-wanted-uk-to-be-us-state-1075874.html; Michael Trinklein, "England, the 51st State?" https://www.michaeltrinklein.com/blog/post7-cmbh5-38tew-2c52t-g7d88-mm8y3; YouGov, "John Humphrys - Britain and America: What post-Brexit relationship should we have?" https://yougov.co.uk/politics/articles/27516-john-humphrys-britain-and-america-what-post-brexit; 45renegade, "The 51st State Thought Experiment," https://45renegade.co.uk/2026/01/20/51st-state-thought-experiment/; UnHerd, "Britain hasn't taken back control," https://unherd.com/2026/01/britain-hasnt-taken-back-control/