Hamas declared years ago, already in the days of Sheikh Yassin, and later even in the New York Times, that it will accept an Israel in the 1967 borders. There is some softening of their position today, in that they put the condition of "the resolution of the issue of refugees", whereas previously this was formulated as "return" of the refugees. The pressure of reality works, or the misfits do not survive. Instead of objecting to reconciliation between Abbas and Hamas, Israel should support it, because then there will be a strong partner for peace. The unfortunate thing today is that it is not clear that Israel is interested in peace.
US rally shows support for ex-Marine held by Iran on spying charges (AP)
from the article: Hamas vows to honor Palestinian referendum on peace with Israel