I've chosen this topic, because I faced it in last few weeks more times then usually. One of my dreams is work in some foreign country. But when you will get opportunity work there you have to answer few important questions to yourself. For someone it can be hard decision. I want to bring up these questions.
If you move out to a different country, you will have to start new life. You can lose contact with your family, friends and your girlfriend or boyfriend. You have to decide if your new opportunity worth for it. You can't visit your parents in Europe from USA every weekend. You don't want to talk to your girlfriend only through Skype. Most of your best friends you will see only on Facebook. If you don't stay in a new country forever it isn't so hard. But I think this is the hardest decision connected with a job in a foreign country.
There can be also cultural difference problems. USA and Europe are closer then Europe and for example China or some arabic country. You have to know what you can expect and don't look through rose-tinted spectacles. You can miss your favorite food or drink too. At first it looks like small problems. But after some time it can be annoying more and more and it can spoil your whole experience.
Last thing that I want to discuss is language. Without proper english you won't probably get opportunity work in foreign country. But you have to consider if your country isn't native english what you will do. It can be hard find new friends outside company in France if you can speak only english.
If you have different questions what bother you and I didn't mention and it, please put them into comments.