For anyone watching the plumes of smoke rising from Gaza in recent days, Hamas dominates the television news and newspaper headlines.

It is not only the publicity, but the status conveyed on Hamas as the Palestinians' principal resistance. Its secular rival, Fatah, sits on the sidelines, marginal to the violence unfolding in Gaza, from which Hamas effectively expelled it at gunpoint in the summer of 2007.

The questions remain: Why did Hamas end its six-month cease-fire Dec. 19? Will it -- can it -- unleash suicide bombers into Israel in retaliation? And will the devastation make Palestinians fall into line behind Hamas, as they reliably have in the past, or lose their support as Gazans count the escalating cost in blood and destruction?

Even knowing that retaliation was certain, Hamas seemed to have ended the cease-fire in part because of its long-standing discipline and consistency: It has preached to Palestinians the rejectionist credo that Fatah negotiated with Israel and got nowhere. Hamas' way of armed force, it argued year in and year out, was the only way.

Hamas' supreme leader Khaled Meshal said Saturday that the cease-fire had yielded few results. If there were no specific benefits -- such as freed prisoners or an end to Israeli blockages on Gaza -- then the option, again, was a return to violence. It may also have calculated that the rockets into Israel -- 60 in one day -- would restore its status among Palestinians as the champion of "resistance" against the Zionist enemy, whose soldiers and settlers are no longer in Gaza within reach of Hamas' military wing.

Tons of bombs

Israel since Saturday has dropped tons of bombs on Gaza in an unprecedented show of force to make Hamas stop its attacks, but it has not said it will try to topple the Islamic militants.

Such a limited definition of goals gives Israel considerable flexibility in deciding when to end the assault, especially if international pressure mounts, while still calling it a success. But this guarded approach also offers Hamas good survival odds, even if the onslaught leaves it badly weakened.

Israel's unwillingness to reoccupy Gaza or openly try to install a new ruler there gives Hamas considerable leverage in future cease-fire negotiations.

In exchange for calm on Israel's border, Hamas demands an end to the crippling blockade imposed by Israel and Egypt after the Hamas takeover of Gaza 18 months ago.

Ending the blockade could help Hamas recover quickly and prolong its rule indefinitely. That, in turn, would all but destroy prospects of an Israeli-Palestinian peace deal.

Israel has been negotiating for the past year with Hamas' rival, moderate Palestinian President Mahmoud Abbas, who controls the West Bank. However, Israel says it cannot implement an agreement as long as the Iranian-backed Hamas, sworn to Israel's destruction, controls half of what would be a Palestinian state.

With peace talks producing no tangible results, a weakened Abbas may not be able to cling to power much longer if Hamas remains in control of Gaza.

Tepid condemnations

Abbas seemed increasingly irrelevant this week, voicing little more than tepid condemnations after the Israeli offensive began. On Monday, Hamas quickly rebuffed his offer to serve as a broker between Israel and the Islamists.

The previous cease-fire between Israel and Hamas, brokered by Egypt, took effect in June. Its terms were never made public, but Hamas says the understanding was that Israel would gradually ease the blockade.

Instead, Israel allowed in only limited supplies, and it repeatedly closed border crossings for sporadic rocket fire on Israeli border communities. With Israel controlling all of Gaza's cargo passages, the closures have led to widespread shortages of basic goods.

Hamas, meanwhile, kept bringing in weapons through smuggling tunnels in preparation for the next round of fighting.

A major question remains whether Hamas expected the Israeli offensive. The outcome, for the moment, is far from clear because neither side has yet deployed the full arsenal available to it.