{
  "last_checked": "2026-10-01",
  "ni_level": "substantial",
  "history": [
    {
      "date": "1968-01-01",
      "level": "low",
      "note": "No sustained terrorist campaign in Great Britain",
      "estimate": true
    },
    {
      "date": "1969-08-14",
      "level": "moderate",
      "note": "The Troubles begin; troops deployed in Northern Ireland",
      "estimate": true
    },
    {
      "date": "1971-01-12",
      "level": "substantial",
      "note": "Angry Brigade bombings, including Robert Carr's home; Post Office Tower bomb in October",
      "estimate": true
    },
    {
      "date": "1972-02-22",
      "level": "severe",
      "note": "Official IRA bombs Aldershot barracks; Provisional IRA mainland campaign begins with the Old Bailey in 1973",
      "estimate": true
    },
    {
      "date": "1974-11-21",
      "level": "critical",
      "note": "Birmingham pub bombings, following Guildford and the M62 coach bomb",
      "estimate": true
    },
    {
      "date": "1975-01-01",
      "level": "severe",
      "note": "London bombing campaign by the Balcombe Street unit",
      "estimate": true
    },
    {
      "date": "1977-01-01",
      "level": "substantial",
      "note": "Fewer mainland attacks",
      "estimate": true
    },
    {
      "date": "1979-03-30",
      "level": "severe",
      "note": "Airey Neave murdered; sustained campaign through the 1980s and early 1990s, including Hyde Park, Harrods, Brighton, Deal, Warrington and Bishopsgate",
      "estimate": true
    },
    {
      "date": "1994-09-01",
      "level": "substantial",
      "note": "IRA ceasefire",
      "estimate": true
    },
    {
      "date": "1995-01-01",
      "level": "moderate",
      "note": "Ceasefire holding, little mainland activity",
      "estimate": true
    },
    {
      "date": "1996-02-09",
      "level": "severe",
      "note": "Ceasefire ends with the Docklands bomb; Manchester bombed in June",
      "estimate": true
    },
    {
      "date": "1997-07-20",
      "level": "substantial",
      "note": "Ceasefire restored; Good Friday Agreement in 1998",
      "estimate": true
    },
    {
      "date": "1999-01-01",
      "level": "moderate",
      "note": "Low mainland activity",
      "estimate": true
    },
    {
      "date": "2000-06-01",
      "level": "substantial",
      "note": "Real IRA attacks: MI6 building 2000, BBC Television Centre and Ealing 2001",
      "estimate": true
    },
    {
      "date": "2001-09-11",
      "level": "severe",
      "note": "After 9/11; reported as “severe general” for several years",
      "estimate": true
    },
    {
      "date": "2005-05-01",
      "level": "substantial",
      "note": "Press reports of a reduction under the internal system",
      "estimate": true
    },
    {
      "date": "2005-07-07",
      "level": "critical",
      "note": "London bombings, then the failed 21 July attacks",
      "estimate": true
    },
    {
      "date": "2005-08-01",
      "level": "severe",
      "note": "After the July 2005 attacks",
      "estimate": true
    },
    {
      "date": "2006-08-01",
      "level": "severe",
      "note": "Threat levels published for the first time"
    },
    {
      "date": "2006-08-10",
      "level": "critical",
      "note": "Transatlantic airliner liquid bomb plot"
    },
    {
      "date": "2006-08-13",
      "level": "severe",
      "note": "Lowered after the arrest of the main airliner plot suspects; airport security restrictions stayed in place"
    },
    {
      "date": "2007-06-30",
      "level": "critical",
      "note": "Glasgow Airport attack and London car bombs"
    },
    {
      "date": "2007-07-04",
      "level": "severe",
      "note": "Lowered after suspects linked to the Glasgow and London attacks were arrested"
    },
    {
      "date": "2009-07-20",
      "level": "substantial",
      "note": "First drop below severe since threat levels were published; security sources called it a finely balanced judgement. No specific reason was given"
    },
    {
      "date": "2010-01-22",
      "level": "severe",
      "note": "Raised after the failed Christmas Day 2009 bombing of a Detroit-bound airliner, amid increased intelligence about al-Qaeda planning; no imminent attack was indicated"
    },
    {
      "date": "2011-07-11",
      "level": "substantial",
      "note": "Lowered two months after the death of Osama bin Laden; the Home Secretary gave no specific reason"
    },
    {
      "date": "2014-08-29",
      "level": "severe",
      "note": "Rise of Islamic State and fighters travelling to Syria and Iraq"
    },
    {
      "date": "2017-05-23",
      "level": "critical",
      "note": "Manchester Arena bombing"
    },
    {
      "date": "2017-05-27",
      "level": "severe",
      "note": "Lowered after police arrested a large part of the Manchester bomber's network; troops withdrawn from the streets"
    },
    {
      "date": "2017-09-15",
      "level": "critical",
      "note": "Parsons Green Tube bombing"
    },
    {
      "date": "2017-09-17",
      "level": "severe",
      "note": "Lowered after arrests in the Parsons Green investigation"
    },
    {
      "date": "2019-11-04",
      "level": "substantial",
      "note": "Lowered after a routine six-monthly review, the first time below severe since 2014. The Fishmongers' Hall attack followed on 29 November"
    },
    {
      "date": "2020-11-03",
      "level": "severe",
      "note": "Attacks in France and Vienna"
    },
    {
      "date": "2021-02-04",
      "level": "substantial",
      "note": "Lowered as the wave of attacks in Europe between September and November 2020 lost momentum; announced on 8 February"
    },
    {
      "date": "2021-11-15",
      "level": "severe",
      "note": "Raised after the Liverpool Women's Hospital bomb, the second UK attack in a month after the murder of Sir David Amess"
    },
    {
      "date": "2022-02-09",
      "level": "substantial",
      "note": "Lowered as JTAC judged the threat was back to its level before the Amess murder and the Liverpool bomb"
    },
    {
      "date": "2026-04-30",
      "level": "severe",
      "note": "Raised after the Golders Green stabbing, reflecting a rising Islamist and extreme right-wing threat"
    }
  ]
}