premise: Israel has put off opening a bus link between the Gaza Strip and the West Bank because of the Palestinian Authority's failure to stop militants from firing rockets on the country, its army chief of staff said Tuesday.
  "Israel has no intention of allowing the passage of convoys between the Gaza Strip and the West Bank while the Palestinian Authority does not act to stop the firing of the Qassam (homemade) rockets," General Dan Halutz was quoted by parliamentary sources as saying.
  Under an agreement in principle reached between the two sides last month brokered by US Secretary of State Condoleezza Rice, the service was to have begun on Thursday.
  The announcement comes as no suprise.
  Last week, Israel froze negotiations on the details, with a spokesman for Prime Minister Ariel Sharon saying: "There will be no discussions about these convoys as long as the Palestinian Authority fails to respect its commitments to fight against terrorism."
   Why did Israel put off opening a bus link between the Gaza Strip and the West Bank?
hypothesis: Israel has no intention of allowing the passage of convoys