Münich Conf... Er, um, White Council
In November 1938, Germany, France, and Britain got together and decided to hand over the Sudetenland, a mountainous region forming a natural defense for the country of Czechoslovakia, to Germany. The Czechs weren't even allowed in the room. Britain and France were their allies. Britain and France thought they'd achieved "peace in out time" by appeasing Hitler. They thought Hitler would go quietly back to Germany and leave everyone alone. In March 1939, Germany invaded and defeated the rest of Czechslovakia. Czechoslovakia remained under occupation until 1945.
At the White Council of 2851, Gandalf is all for going after Dol Goldur because now they know it's Sauron who has taken up residence as the Necromancer there. But Saruman counsels that they wait and watch Sauron and try to see what his designs are. Ever wonder how Thranduil felt about that decision? (This assumes, of course, that he was not invited to the Council. The Council takes place 90 years before Bilbo finds the Ring. Thranduil and his people are the ones to live with the decision reached at the Council.
Take the above snippet of dialogue, keep the Munich Conference (from the Czech's point of view) and run with it. Thranduil should have a good amount of attitude, and deservedly so. Yet no evil Thranduil's need apply, please. Ticked-off Thranduils, however, are fair game!