jerusalem shooting a retaliative measure?

DEBKAfile reports that the line of investigation developing the day after a Palestinian terrorist murdered 8 Israeli yeshiva students in Jerusalem is that the Hamas command in Damascus, or Hizballah in Beirut activated the killer, Ala Abu Dhaim 25, a Palestinian with Israeli citizenship from Jebal Mukaber in S. Jerusalem.
Hamas-Gaza first took responsibility for the massacre, then backtracked.
The gunman sprayed automatic Kalashnikov fire on group after group of students studying Thursday night, March 6, in the library of the Yeshivat Harav center in Jerusalem.
After the killer’s family raised Hamas and Hizballah flags on their mourning tent, Jerusalem police arrested more than 10 of his relatives and friends. Hamas celebrated the attack in Gaza as “heroic.”
DEBKAfile’s political sources report that an explicit Hamas admission would present the Israeli government with a dilemma. It has already drawn up a detailed plan of action to fight Hamas in Gaza over its rocket blitz against Israeli civilians. Trying to play down the issue of responsibility, the police commissioner Dudi Cohen said the attack may have been an isolated incident. At the same time, the security preparedness across the country was extended to the whole of next week and the West Bank sealed.

In American media, these attacks seem fairly unsolicited (other than the usual "Jews stealing my land" response of the Palestinians).
But: just a day before, Debka reported this:
Exclusive: Israeli cabinet okays Hamas, Jihad Islami targets for attack

DEBKAfile’s military sources disclose that Israel’s security cabinet approved Wednesday, March 5, a series of terrorist targets for early attacks as part of a sustained military offensive against escalated Palestinian attacks from Gaza on Israeli civilians.
Prime minister Ehud Olmert and defense minister Ehud Barak earlier obtained a quiet nod from US secretary of state Condoleezza Rice before she wound up her visit. These targets are revealed here by DEBKAfile:
1. Chiefs and senior officers of Hamas’ and Jihad Islami’s armed wings.
2. Their senior political officials in the Gaza strip, excluding prime minister Ismail Haniyeh, but including hard-line Mahmoud a-Zahar.
3. Hamas and Jihad institutions, including police stations.
These decisions were taken at the security cabinet’s first exhaustive review of Israel’s Gaza options.
DEBKAfile’s sources reveal the ministers considered demolishing urban districts in Gaza which serve as launching pads for missiles after evacuating their inhabitants. No final decision was reached on this.

just a thought.