Being called for compulsory military service on 30 March 1948, Paul was first assigned to be stationed in Bitburg, Western Germany, where he completed his military training. His mandatory term coming gradually to an end, he reentered the Army in 1949 because he was offered the prospect of being detached to the Douanes (D.A.L.). The promising career in customs should not come true, so he stayed in the military as a driver. In 1950, following the motive to serve his country after World War II, he volunteered to fight as part of the first contingent in the Korean War. 

On his return from Korea, Paul noticed the heated, nearly hateful, atmosphere in the Army which turned specifically against Korean veterans. Consequently, he took a new job at the lime works in Contern, before he transferred to the C.F.L. due to better payment. In 1952 he married his wife Cathy, with whom he had two children.