Sports as a Bargaining Chip?

Okay, I need some help understanding something.

On the news today was yet another story of the proposed sanctions against the Iranian soccer team at the Worlds by the USA in roder to "force the governing parties into addressing the build of weapons."  Recognizing that this has been a historical tact used by countries to make the banned country realise the errors of their ways but come on.  With the 1980's boycot of the USSR Olympics actually contribute to the Wall coming down?  Did the IOC ban on South Africa bring an end to the racist regiems?

The only thing that will come about as a result of a ban on the World Cup qualified Iranian team will be anothe black eye for those that push for it.  If people think that they have seen fanatical ideology in the past, try to prevent a Qualified Team from competing.....  And, this is not to make any slight but Soccer in other parts of the world is much like a religion.....  Why even go there?

The next story was about the Woldchampionship of Baseball which is taking place in the USA this year.  Apparently, CUBA has been banned from the event because of the old 1959 embargo and the laws that prevent the financial gains by the Cuban people by the USA (Believe me, there is a law!!!!)  So the Visa weren't approved and the players have lost out.  Fidel (aside from being a major baseball freak is apparently a PR master) then turned around and said, "Well then, all the money that we would have gotten from gate receipt shares will be DONATED to victims of Hurricane Katrina."  Now the American administration has to try and figure out how to ban them for "other reasons" and save face while doing it....  I'm sure this ban wll lead to the fall of Fidel Castro's Communist regiem!

Who sufferes in the end?  Do you guys really believe that these bans and embargos work?  If so, why?