Martti Johannes Kari (17 November 1960 – 30 August 2023)[1][2] was a Finnish cyber security and hybrid warfare expert and retired military intelligence officer.

[4] He stayed with the military and was commissioned as an officer, first at the Armoured Brigade, later moving to the Signal Regiment.

[4] During his career, he served in a number of roles in the Finnish Defence Forces, including as a deputy head of intelligence at the Defence Command, director of the Centre for signals intelligence (Viestikoekeskus [fi]), and military attaché at the Finnish Embassies to Warsaw and Kyiv.

[5] He also contributed to the structural reforms of the Ukrainian military intelligence activity in 2020 as a strategic advisor.

'Russian strategic culture – why Russia acts the way it does') was published online and went viral on YouTube with 1.8 million views as of December 2023, making it the most-viewed Finnish university lecture of all time.