A political movement requires the support of its people, if one wishes to undermine a political movement it might be argued that it is pragmatic to support a divisive extremist group to disrupt the political unity of that movement. But watch out, supporting extremists may be costly in the long run.
So Israeli 'intelligence" created a religious extremist party to oppose a secular coalition whose mass movement was forcing Israel to an international conference! There are other stories on this site, which takes a critical look at all forms of extremism and violence mongering and suggests how the policies of retaliatory response has feed the cycle of violence.
Overcoming colonialism through faith and action.
The pre 1987 Hamas was legal organization and some say it was financed by Mossad to counter the Communist and Christian PLO.
Ahmed Yassin took over Hamas in the later 80s and it became the terrorist organization we know today.
As for unprincipled actions. I think Sharansky got it beste when he said,
Oslo failed because the democratic world, including Israel, thought that peace could be made with a dictatorship.
Lebanon and Israel are paying the price for that unprincipled failure today.
Nothing in Hamas program has changed. Israel took a weak and disorganized group of fundamentalists and created an organization that they can't negotiate with. They could negotiate land for peace with the PLO, which advocated a secular, plural, democratic state.
Israel's own stupidity has created most of its problems.
geez, I even made Wikipedia along with L'Humanite as a source on Hamas funding.
However, various sources, among them United Press International [31], Le Canard enchaîné, Bill Baar and L'Humanité[32] have highlighted that Hamas' early growth - before its official founding and the creation of the military branch - had been supported by the Mossad as a "counterbalance to the Palestine Liberation Organization (PLO)".
But it's the pre-1988 Hamas Clyde, before the charter.
Here are links which I couldn't anchor,
http://en.wikisource.org/wiki/Hamas_Covenant
http://en.wikipedia.org/wiki/Hamas