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.