TEL AVIV - Despite heavy air and ground assaults, Israel has yet to cripple the military wing of Hamas or destroy the group's ability to launch rockets, Israeli intelligence officials said, suggesting that Israel's main goals in the conflict remain unfulfilled after 18 days of war.

The comments reflected a view among some Israeli officials that any lasting solution would require either a breakthrough diplomatic accord that heavily restricts Hamas' military capabilities or a deeper ground assault into urban areas of Gaza, known as a possible "Phase Three" of the war.

The intelligence officials said there were some signs that the military assault had undermined Hamas' political cohesion and that Hamas leaders in hiding in Gaza were more eager for a cease-fire than leaders in exile. They said this assessment was based on hard intelligence, presumably phone intercepts.

The military wing of Hamas has been hit "to a certain extent" with "a few hundred" Hamas fighters killed during the ground offensive that began midway through the war, the intelligence officials said. Hamas is still able to launch 20 to 30 rockets a day, including five to 10 missiles of ranges longer than 20 kilometers, or about 12 miles, down by a third from the start of the war, the officials said.

Greater damage has been done to Hamas' capacity to run Gaza, with a large number of governmental buildings destroyed over the course of the operation, they said.

The Israeli army's chief of staff, Lt. Gen. Gabi Ashkenazi, speaking to parliament on Tuesday, said that "we have achieved a lot in hitting Hamas and its infrastructure, its rule and its armed wing, but there is still work ahead."