The killing of senior Hamas official Nizar Ghayan Thursday in an Israel Air Force strike in Jabalya is a significant development at this stage of the war in the Gaza Strip, due not only to his high position in the Gaza leadership but also because of the message his assassination sends to the Palestinians.

Gazans have been asking Haaretz why Israel is hitting Hamas foot soldiers, empty buildings and innocent civilians rather than the leadership. They see this as proof of Israel's inability to really deal with Hamas. Ghayan's killing shows that Israel is no longer hesitating. The Hamas leader in Gaza, Sheikh Ismail Haniyeh, his government and certainly Hamas military leaders such as Ahmed Jabri know they have good reason to stay in hiding.

The assassination in the spring of 2004 of Abdel Aziz Rantisi and Ahmed Yassin was the main factor behind the Hamas decision to suspend suicide bombings and limit friction with Israel.

But these killings also increased sympathy for Hamas in Gaza and led to its electoral win two years later. In the same way, Hamas television quickly made use of Thursday's incident, repeatedly showing footage of Ghayan's headless body.

Meanwhile, the widely anticipated ground offensive was delayed again Thursday for operational reasons and because Foreign Minister Tzipi Livni was in Paris to meet with President Nicolas Sarkozy. France is taking advantage of the slow U.S. response to play a central role in efforts to reach a cease-fire.

Almost a week into the war it now seems clear that Israel missed a golden opportunity in the first or second day to end the operation as a reprisal action only. The government says it is giving the IDF a chance to achieve the maximum, but in reality the air strikes were to have given the government time to come up with an exit strategy. That did not happen. As a result, Hamas is rallying somewhat while Israel is sliding toward a a ground operation that holds many risks.

The battle is being conducted in the shadow of a looming, election-eve political crisis, with tensions especially high between Livni and Labor Party chairman and Defense Minister Ehud Barak. The latter gained points early in the operation but in the past two days his mood seems to have soured, following media criticism after it was leaked that he was willing to consider a cease-fire before a ground offensive.

The Southern Command expects that a ground offensive will cause Israeli casualties but achieve its aims of increasing the direct threat against Hamas. However, the delays in the start of the ground operation are taking their toll.

Unlike the Second Lebanon War, the ground war in the Gaza Strip will be waged in densely populated urban areas. The civilian population in Lebanon fled during the fighting. In the Gaza Strip, however, there is nowhere to run but the beach and the Egyptian border, and many civilian casualties can be expected.