Wasn't the Atlantropa thing envisioned by some architect who wanted to bring unity and economic growth to a Europe that was desolated by WW1? His idea was that by draining the Mediterranean it would create create new lands to settle and develop with farms and factories, of course he didn't know that by draining the Mediterranean most of Southern Europe would turn into a wasteland similar to the Sahara desert and that the new land would be infertile. This idea was also extremly unrealistic, because in order to drain the Mediterranean you would need to build dams on the straits of Gibraltar and Constantinople, also close down the Suez Canal, no nation on Europe would do any of these things because all of those straits are vital for economics and military strategy.