I think any relationship depends on communication. If you can't be honest and clear through mail or phone, I don't see how it would make any difference face-to-face. My cousin's boyfriend had to go to Japan (in the Navy) quite soon after they started going out and they got to know each other quite well. He came home a year and a half later to get married... I suppose it just depends on the couple, but I don't know. I shouldn't be a dating counselor. 
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How dull it is to pause, to make an end,
To rust unburnish'd, not to shine in use!
As tho' to breath were life.
