MM has hit the nail. I'm 8 years overseas, after 7 years in the UK. If you are young without attachment, being overseas can be a worthwhile experience full of adventure. If you have commitments, it has to be viewed cautiously. In my UK northern base it is almost impossible for me to find work again as I'm simply relatively expensive and not current with UK curriculum. One assumes my motivations for being abroad would also be questioned by many employers. Get onto the job seekers forum (and on this one) and see how many are applying unsuccessfully for positions. A two years contract overseas offers little stability and your next post depends so much on the randomness, in many cases, in trusting your career to a unknown overseas instituion, which you may not recover from. I am now a committed to overseas teaching until retirement; fortunately it suits me, but that is a big step and one you may not be able to take with as much freedom as me. Just to confuse matters more, persoanlly it is the best thing I ever did.