Wrong, A Brit named Whittle invented the jet engine and was working on it in 1930. The German's first jet engine, the HeS-3 that burned liquid fuel wasn't even bench tested until March 1938. It far more likely that the Germans stole the idea from the British as Whittle was working for a private company and nothing he was doing was classified before the war. Robert Goddard launched the world's first liquid fueled rocket in March 1926. The Germans didn't launch their first liquid fueled rocket until 1932. With no governmental support Goddard was launching liquid fueled rockets all through the thirties. The Germans led by Von Braun developed the first ballistic missile because bombers couldn't survive in Allied airspace. It cost most to loft a one-ton warhead 190 miles than any damage that warhead could do.