Jaroslav Klemeš went into exile in 1940, before the age of 18, and soon took part in the fighting on the French front as a soldier in the Czechoslovak army. After retreating to Britain, he was selected and trained for special operations in the Protectorate. On 17th February 1945, he was as a member of the Platinum-Pewter group dropped near Nasavrky. Initially he took part in the resistance in the Bohemian-Moravian Highlands, later moving to Prague at the end of the war, where he worked as a radiotelegraph operator until the liberation, maintaining contact with London and the government in Košice.
After the war, Jaroslav Klemeš remained in the army and the events of February 1948 found him in Litoměřice, serving in the Signal Corps at the rank of first lieutenant. In the fall of 1949, he was arrested, demoted, expelled from the army, and sentenced to two years in prison for “failure to report the crime of treason”. The reason was that he had failed to report the escape of two of his fellow soldiers across the border shortly after February 1948. After his release from prison, he was placed for two more years in a forced labour camp in Ústí nad Labem, where he was ordered to permanently reside after his release. Eventually, however, he married, started a family and settled in Ústí.
In May 1968, he was judicially rehabilitated and his rank and decorations were restored. However, he did not receive an actual moral rehabilitation until after November 1989, which is evidenced by an army identity card issued at that time. In May 2010 he was appointed to the first general rank and in 2016 he was awarded the Order of the White Lion. Gen. Jaroslav Klemeš died on 7 August 2017 in Prague.