Operation Tannenbaum Operation Tannenbaum Operation "Tannenbaum ("Fir Tree"), known earlier as Operation "Grün ("Green"), was a planned but cancelled invasion of Switzerland by Nazi Germany and Italy during World War II. For tactical reasons, Adolf Hitler made repeated assurances before the outbreak of the Second World War that Germany would respect Swiss neutrality in the event of a military conflict in Europe. In February 1937, he announced that "at all times, whatever happens, we will respect the inviolability and neutrality of Switzerland" to the Swiss federal councillor Edmund Schulthess, reiterating this promise shortly before the Nazi invasion of Poland. These were, however,
Allen Tannenbaum thesis advisor Heisuke Hironaka at the Harvard University in 1976. Tannenbaum has done research in numerous areas including robust control, computer vision, and biomedical imaging, having almost 500 publications. He pioneered the field of robust control with the solution of the gain margin and phase margin problems using techniques from Nevanlinna–Pick interpolation theory, which was the first H-infinity type control problem solved. Tannenbaum used techniques from elliptic curves to show that the reachability does not imply pole assignability for systems defined over polynomial rings in two or more variables over an arbitrary field. He pioneered the use of partial differential