[4] In 1946, Kivimäki together with half-a-dozen other leading politicians were put on "war-responsibility trials" executed under pressure from the Allied victors in World War II.

Kivimäki was sentenced to five years in prison after being found responsible for the Continuation War.

After Finland signed the Paris Peace Treaties, 1947, and the Finno–Soviet Agreement of Friendship, Cooperation, and Mutual Assistance, 1948, the international situation was deemed somewhat stabilized, and Kivimäki was pardoned.

During the era of finlandization, many prominent Finns expressed themselves cautiously on such subjects in order not to disturb sensitive Allied victors of the war; a cautiousness that without doubt influenced Finland's post-war generation's understanding and views.

Kivimäki without any doubt occupies a prominent position among pro-Axis Finnish leaders.