From what I understand it was Israel ignoring Hamas and letting them grow in the 80's that helped create the current problem. I think they were seen as a counterweight. They needed to be dealt with ASAP not left to consolidate.
Bush administration has some explaining to do on Hamas
White House: OK if Hamas controls PLC- "business professionals...not terrorists"
ROP Ping!
ARUTZ SHEVA.com: "HAMAS BOMB-MAKER STAR OF SYRIAN PRODUCED TV SERIES A 12-part series on the life of the “father of suicide bombings,” Hamas bomb-maker Yihye Ayyash is set to be aired on the Lebanese-based Hizbullah satellite television station al-Manar." (April 18, 2005)
JIHAD WATCH.org (YNET): "PALESTINIAN GIRL HIDES GUN IN UNDIES" (ARTICLE SNIPPET: "The soldiers in the Balata refugee camp, a terrorist hotbed, found the gunman inside his house and ordered him to surrender his weapon. He refused, saying he didn't have it. After questioning, they found the man's sister had hidden it her underwear. Troops then arrested the Hamas terrorist. They also found a gun holster and bullets inside the building.") (April 16, 2005) (Read More...)
WorldNetDaily.com: "DOCUMENTS SHOW ARAFAT PAID FOR DISCO BOMBING Sent Thank-You Note to Family of Terrorist Who Killed 21, Injured 120" by Aaron Klein (ARTICLE SNIPPET: "The attack on the Dolphinarium was one of the most brutal massacres of the Palestinian intifadah, killing 21 people, mostly teens, on a Friday night in June 2001. More than 120 people were injured in the powerful blast carried out by Hamas terrorist Hassan Khutari.") (September 15, 2004)