Historical clue formulations

• Intl. org. with 12 stars on its flag — 2025-12-25
• From which Britain "Brexited," for short — 2024-09-09
• Western bloc since '93 — 2024-05-23
• What was exited during Brexit — 2023-07-30
• Grp. with a 12-star flag — 2023-06-21
• Bloc that no longer includes Great Britain, for short — 2022-08-23
• Grp. established by 1992's Maastricht Treaty — 2022-04-21
• What Britain voted to Brexit from, for short — 2019-05-01
• 2012 Nobel Peace Prize recipient, informally — 2018-12-08
• What's exited in Brexit, for short — 2018-10-09
• What's exited in Brexit — 2017-02-03
• Grp. whose flag has 12 stars — 2013-04-05