Historical clue formulations

• Intervene — 2026-02-25
• Get involved — 2025-10-19
• Intervene — 2025-06-17
• Sub — 2022-09-03
• Attempt to play peacemaker — 2022-03-05
• Enter, as a foyer — 2021-08-30
• Intervene — 2020-11-22
• Substitute (for) — 2019-04-10
• Start to break up a fight, say — 2014-03-13
• Enter as a mediator — 2013-10-12
• Enter — 2008-07-21
• Enter — 2007-01-07
• Intervene — 2003-11-19
• Cross the threshold — 2001-04-01
• Attempt to mediate — 2001-02-20
• Intervene — 1999-06-17
• Enter — 1997-06-23