In early 1939, a Saudi delegation went to Nazi Germany to negotiate an arms agreement, part of which would have been diverted to Palestinian Arabs fighting Jewish immigrants in the British mandate of Palestine. At least some of the Saudi group met Adolf Hitler at his mountain top hideaway at Berchtesgaden.
German arms never reached the kingdom — or Palestine – as the Saudis could not afford to consummate the deal (that was in the days before the oil revenues started flowing in). However, King Abdullah still treasures a dagger given as a gift from the Fuhrer himself, and occasionally shows it off to guests.
Visiting U.S. officials are briefed in advance so they can display appropriate diplomatic sang-froid if Abdullah points out the memento.
No word on whether King Abdullah ever let Barack Obama play with his dagger.