The crisis in Greece affect the euro very much. If the problem is not solved in near time or if Greece doesn't leave the European Union than the euro will drop. That is the reason why the union has to do something about this 
the european union will do everything to keep greece inside. if that means giving them more billions that they will never get back, then they will still do it. if greece leave the euro and it turns out to be great for them, then other countries may decide to leave as well. stakes are way too high.