Canada, home of hockey, did not send a hockey squad to either the 1972 or 1976 Winter Games. As well they boycotted the World Championships up until 1977.
Canada was awarded host country honours for the 1970 World Champioships for the first time ever. The tournament would be held in Montreal and Winnipeg and the newly formed Hockey Canada felt it was the opportunity to address the issue of amatuerism with the IIHF. Canada wanted the Championships and Olympics open to all players, professional or not.
The IIHF agreed to allow nine non-NHL professionals to compete for each team. The first test of this was the Isvestia tournament in Moscow in December 1969. Although Canada used only five minor league pros, they still managed a close second place finish. This prompted the IIHF to hold an emergency meeting immediately after the tourney, and president Avery Brundage went back on the original terms and announced that any professional players at any level not be eligible to compete at the Olympics. This of course did not please Hockey Canada.
The contention was that for all intents and purposes, players of the Soviet Union were professionals. They were amateurs in name only in the eyes of Canadian hockey officials. One day after the IIHF's backtracking, Canada decided to withdraw from international competion and would decline hosting the 1970 Worlds. In reality, Canada's pure amateurs were in fact still very good players, but by the early 70's they clearly were not the best amateurs if the Soviets were included in the mix. Of course when the best-on-best was played for the first time in 1972, Canada just barely beat the Soviets (albeit without Orr and Hull).
Canada would continue the boycott through the 1972 and 1976 Olympics. In '76 however, they were joined in protest by Sweden, Norway and East Germany. In response, the IIHF announced that beginning with the 1977 World Championships, professionals would be allowed. Canada immediately agreed to compete the following year. Still the International Olympic Comittee held their ground and only allowed "amateurs" to compete.
The IIHF may have relented on the amateur rules but they did not make it easy on Canada as the World Championships were held at the end of April when the NHL (and it's predominance of Canadians) were still in the playoffs. This meant of course that many of the best players were still involved with their pro teams. On top of this, the IIHF refused to allow players to play without helmets which proved to be another disadvantage for Canada.
The first re-entry into world competetion for Canada was a fine team of NHL'ers including Phil and Tony Esposito, Pierre Larouche, Wilf Paiement, Jean Pronovost and Summit Series veterans Ron Ellis and Rod Gilbert. However, there was nobody on the team that finished higher than 12th in NHL scoring in 1976/77 and Ron Ellis had was just coming off his second season of retirement. This squad would go 6-3-1 overall and finish fourth behind the Czechs, Sweden and Russia. Canada actually ended up playing gold medalist Czechoslovakia to a 3-3 tie and beat them 8-2 and also went 1-1 against Sweden, however they were lit up by the Soviets 8-1 and 11-1 knocking them out of the top three.
It is interesting to wonder if in fact Canada would have won more medals in the Worlds or Olympics if the ridiculous amateur status rules were abolished far earlier. Perhaps we wouldn't have had to wait until 2002 for a return to the gold medal podium in hockey.