On Being Apart

What is it that makes being apart different from breaking up?  We can all agree that the physical separation is the same.  Then it must be in the emotional side of things.  In being apart, there is the point at which you are together again to look forward to.  An anticipation of something good which helps you stay the path; a vista at the of of a mountain or a peaceful lake at the end of a long hike.

Let's now suppose the the joy of reunion doesn't exist or, as the case may be, may not exist.  Is this situation harder or easier to cope with than the original?  (These are, of course, rhetorical questions as I haven't done much more thinking on this than to just come up with the questions.)

My gut reaction is is it's harder as the uncertainty of joyful reunion or tearful separation on return loom over the situation.

I'll come back to this when I may have some answers.