In a report presented on 30 June, OKW Chief of Staff Alfred Jodl reviewed options to increase pressure on Britain to agree to a negotiated peace. The first priority was to eliminate the Royal Air Force and gain air supremacy. Intensified air attacks against shipping and the economy could affect food supplies and civilian morale in the long term. Reprisal attacks of terror bombing had the potential to cause quicker capitulation but the effect on morale was uncertain. Once the Luftwaffe had control of the air and the British economy had been weakened, an invasion would be a last resort or a final strike (""Todesstoss"") after the UK had already been practically defeated, but could have a quick result. At a meeting that day, OKH Chief of General Staff Franz Halder heard from Secretary of State Ernst von Weizsäcker that Hitler had turned his attention to Russia. Halder met Admiral Otto Schniewind on 1 July, and they shared views without understanding each other's position. Both thought that air superiority was needed first, and could make the invasion unnecessary. They agreed that minefields and U-boats could limit the threat posed by the Royal Navy; Schniewind emphasised the significance of weather conditions.