You would be surprised about some of the countries that have once participated at the Olympic Games. Regions such as Saarland and Bohemia participated at previous Games, but no longer exist independently. The Saar existed from 1947 to 1956 in part of Western Germany that was occupied by France, and only competed at one Olympics in 1952 before joining Germany. Bohemia athletes competed at the Olympic Games between 1900-1912. After World War I, Bohemia became part of the new Czechoslovakia, which itself lasted until 1993 when it split into the Czech Republic and Slovakia.
Then there are short lived unions, such as The United Arab Republic which was made up of Egypt and Syria, and the West Indies Federation, a combined team from Jamaica, Trinidad and Tobago and Barbados. Both of these teams competed at the Olympics only once, in 1960.
What about athletes with no team – athletes from Macedonia, Montenegro and Serbia competed as Independent Olympic Participants in 1992, and athletes from East Timor competed as Individual Olympic Athletes at the 2000 Summer Olympics. Also, after the break up of the Soviet Union, the independent states competed under the banner of The Unified Team at the 1992 Olympics in Barcelona.
I wonder which teams competing in 2012 in London will one day join this list of past teams. Border disputes and wars will continue, and the countries of the world will continue to evolve. But, no matter what, most athletes will have a country to compete for, even though the names may change.