The goal "weaken Hamas" provides the wrong starting point. "Coming to an understanding" should be the goal. . Ignored by Israel and the world, Hamas came with contructive proposals, especially in the 2005-2007 period. Many times they said to accept a solution negotiated by the PA and accepted by a Palestinian referendum.. If you state the goal "weaken Hamas" of course Hamas will act against you and the description "terrorist organisation"will become a self fulfilling prophecy.
from the article: Weaken Hamas through diplomacy