It seems to me that all too many people have forgotten that had there been no Israeli occupation of the West Bank and Gaza there would be no Hamas. Hamas did not become a factor until the Palestinians had suffered over 20 years of Israeli oppression and domination. Hamas began as a charitable organization, which it still is, and was originally supported by Israel as a counterweight to the secular PLO. But when the PLO showed the Palestinians that it could not deliver their lands in the West Bank and Gaza or end the occupation even after they recognized Israel in 1988 many people turned to Hamas, To put the situation in four words: No occupation. No Hamas.
Abbas: West Bank arson is a 'crime against humanity', vows to petition ICC (Haaretz)
from the article: U.S. to Israel: Probe alleged Gaza war crimes to advance peace