Following graduation, Paul joined the family’s business and helped his parents in their hotel, the Hotel Beau-Séjour in Mondorf-les-Bains. As a certified chef, Paul mainly worked in the kitchen. Two years into German occupation, Paul voluntarily joined the Wehrmacht in 1942, at the young age of only 17. Called to the military airfield in Kaufbeuren, he first joined the Luftwaffe and became a paratrooper (Fallschirmjäger). Later he fought against Allied troops in Italy, a story he liked to share with other veterans in Korea. 

Facing no legal consequences after the war, Paul was eligible for conscription into the Luxembourg Army in November 1949. Despite an exemption request from his parents, who needed their son to run the kitchen, Paul had to report for duty. In September 1950, he decided to join the first contingent. During the Korean campaign Paul proved his sense for military tactics and strategy on multiple occasions.

Back from Korea, Paul left the military and continued to run his own family hotel and restaurant under his nickname “Beau-Séjours Paul” until the 1980s.