SCENARIOS: Israel's options in Gaza

(Reuters) - Israeli air strikes killed at least 205 Palestinians in the Hamas-ruled Gaza Strip, stoking fears of a broader conflict.

Here are some of the choices facing Israeli leaders, who are enmeshed in an election campaign:

ALL-OUT INVASION

PROS:

-- The best-equipped army in the Middle East, with total control of the air, could overwhelm Hamas guerrillas and their allies, who may number around 35,000.

-- It might quiet critics in Israel who demand forceful action after rocket attacks from the coastal enclave. One Israeli was killed on Saturday, the only fatality in two months of lopsided skirmishing in which about a dozen Gaza militants were killed in Israeli air strikes before Saturday.

CONS:

-- Despite a massive superiority in firepower, taking and holding the urban jungle of Gaza's Palestinian refugee camps would certainly cost Israeli lives, even if lessons have been learned from the 2006 Lebanon war against Hezbollah, when 114 Israeli troops were killed in a month of fighting. Hamas might also kill Israeli soldier Gilad Shalit, whom it captured in 2006, and try to nab others.

-- A botched ground operation could backfire on Israeli political leaders competing in a February 10 election to replace outgoing Prime Minister Ehud Olmert. Foreign Minister Tzipi Livni, who heads the centrist Kadima party, has been vague about how far the campaign should go. Defense Minister Ehud Barak of the left-leaning Labour party has warned that even a large-scale ground operation may not succeed in stopping all the rockets.

-- Hamas may unleash longer-range Grad rockets on bigger cities like Ashkelon and Beersheva.

-- Heavy fighting would cause casualties among Gaza's 1.5 million civilians, half of whom are children. In Lebanon, 900 civilians died compared to 300 Hezbollah fighters. Israel risks condemnation abroad, and potentially even sanctions.

-- Though Palestinian President Mahmoud Abbas shuns Hamas, a bloodbath in Gaza would put Abbas under huge domestic pressure to break off U.S.-sponsored peace negotiations.

-- Retaking Gaza would leave the problem of whether Israel would resume the occupation it ended in 2005 after 38 years. It has vowed not to. But withdrawing after an invasion might see more hostilities from even more embittered Gazans. There has been talk of foreign peacekeepers, as in Lebanon -- but few nations have much appetite for taking on Gaza's problems.

LIMITED FORCE

PROS:

-- Some Israeli officials speak of a swift move into parts of the 45 km (30-mile) long strip of coast, notably into the relatively thinly populated "Philadelphi Corridor" in the south that would cut Hamas off from supply tunnels from Egypt and into northern areas from which rockets are hitting Israel.

-- Such a move, officials say, could be accompanied by air strikes and commando operations to kill the Hamas leadership and let Abbas's Fatah loyalists take control of the enclave.

CONS:

-- Even a limited operation risks a large number of casualties on both sides.

-- It is unclear how hard it may be to dislodge Hamas even without senior leaders, and the rocket fire might continue.

-- Although Fatah has hundreds of thousands of supporters in Gaza, Hamas routed its forces in June. Hamas has pushed hard a message that Abbas is collaborating with Israel. And Hamas's 2006 election win confirmed its popularity in Gaza.

SANCTIONS

PROS:

-- Israel has shown it can seal off Gaza quite easily.

-- By pushing Gazans to make a connection between hardship and Hamas rule at a time when aid money is flowing into the Fatah-run West Bank, Israel, its Western allies -- and Abbas -- hope Palestinians in Gaza will turn against the Islamists.

CONS:

-- Sanctions so far have had little obvious effect on Hamas.

-- Sanctions have drawn international condemnation and accusations Israel is breaking the Geneva Conventions because it is still effectively the occupying power. Hamas scored points with many when it forced open Gaza's Egypt border earlier this year.

-- The embargo has hit Israeli businesses which long sold into Gaza and bought Gaza's fruit, flowers and other goods.