The United Kingdom is entering a period of heightened geopolitical instability and faces aplurality of threats from rival great powers, terrorist groups and in the cyber domain as well as fromdomestic political instability. Islamist terrorism is the most immediate and active threat to the UK, with 3attacks in 3 months in 2017 that have strained the UK's security apparatus. Mounting geopoliticalchallenges to the US-led post-Cold War International order in Eurasia - which has been crucial to the UK'sprosperity and security - represent a more serious, long-term threat. The UK faces further uncertainty dueto the Brexit process - begun in March 2017 - which will offer headwinds to the economy although we doubtthat it will fundamentally damage the UK's security relationship with its European neighbours. We expectthat relatively sluggish economic growth to 2020 may force the MoD to revise its spending plans in thecoming years although defence expenditure will still remain above the 2.0% of GDP NATO-stipulatedtarget.