I hate it even more when this similar situation happens twice in the same game. I ran into this problem with oil resources. Other than a couple of off-shore reserves (which it would take too long to tech up to utilize), the only close oil reserve was in an unclaimed tile one tile outside of my borders. Naturally, a neighboring civ, despite my efforts to make my borders expand, expanded on to the title and now I have no alternative than to declare war yet again, or wait to develop the techs needed to use the off shore deposits, which will let everyone catch up the tech race. What's ironic is that the neighboring civ can't even develop the oil tile and probably doesn't even know they are sitting on it. Anyway, "To war, to war! We're going to go to war! Sing hiddy hiddy hiddy hiddy hiddy hiddy ho!" to quote the Marx Brothers.