Oh, we have several attempts to assassinate Hitler. In 1938, Generals planned to stop the upcoming war by revolting before the troops marched to Prague. But unfortunately, the Munich treaty prevented a success. And then, the leader of the revolt resigned.
In 1944, a bomb exploded in the headquarters where Hitler had a meeting. Unfortunately, Hitler was just wounded and survived the attack. Col. Stauffenberg and his supporters, who planned the assassination in 1943, didn´t think of a suicide mission. (This would be today´s favouritie solution to make sure someone dies.) He and his closest supporters were shot the same day at the building which is now the German Federal Ministry of Defense. Hundreds of alleged or factual supporters were convicted and killed during the following months. Even Rommel was forced to committ suicide because of that.
Yes, I remember. Also saw the documentary on it a year or so ago, but I forgot about Rommel. Today's weaponry has changed the playing field and the risk. Regarding Iran, it would not surprise me if we see a state funeral over there pretty soon if anyone in the know there is certain the crazy man is really going to launch. I think cooler heads will prevail.