"On the 18.04.1941 Oberstleutnant Decker distinguished himself while leading at the head of Kampfgruppe Balck. He and his troops crossed over the Pinios, broke through the Australian/New Zealanders’ fortified line, thrusted towards Larissa and thereby forced the enemy to give up their Olympus position. By smashing the Yugoslavian defense in the Strumica basin he created the necessary conditions for the 2. Panzer-Division’s thrust to Salonika." his Knight's Cross of the Iron Cross citation, awarded on June 13, 1941.
"For the outstanding leadership of the 5. Panzer-Division north of Rogatschew in the time period 22.02.-21.03.1944 and the subsequent relief battles at Kovel. On the morning of the 05.04.1944 contact was established with an outermost strongpoint of Fortress Kovel; the villages of Dubowa and Rudniki (northwest of the city) were taken." From his Knight's Cross to the Iron Cross citation with Oak Leaves, awarded on May 4, 1944.
"For the thrust of Panzer-Division Clausewitz under his Korps command. Decker’s mission was to thrust from the Uelzen area towards the south via Helmstedt, with the ultimate aim of establishing contact with the 11. Armee in the Harz. Initial successes were achieved, and these led to the occupation of the bridges over the Weser-Elbe canal at Fallersleben. The Division thereby accomplished its mission of tying down enemy forces and relieving the pressure on our forces positioned at the Elbe river on both sides of Magdeburg." from his Knight's Cross to the Iron Cross with Oak Leaves and Swords citation, awarded on April 26, 1945.
Another deadly enemy elite,