BEIRUT (AP) - Lebanese voters face a stark choice Sunday between renewing the mandate of a pro-Western coalition or handing power to a Hezbollah-led alliance that could bring international isolation and new conflict with Israel upon the small, tumultuous country.

A win for the Shiite militant group and its allies in the parliamentary vote would set back U.S. Mideast policy and boost the influence of Hezbollah backers Syria and Iran. It would also give Hezbollah, which the United States considers a terrorist organization, a major say in the formation of Lebanon’s government for the first time.

But Hezbollah’s Christian allies argue that a victory by their coalition will not have such a dramatic impact and will ensure peace in a nation where tensions among the Christian, Sunni and Shiite populations have repeatedly threatened to explode into civil war in the past four years.

They say that involving Hezbollah more deeply in the political process - rather than shunning it - is the only way to bridge the sectarian divides.

Their opponents counter that Hezbollah would be driving Lebanon into the arms of Iran, which could use it as a front in the Islamic republic’s confrontation with Israel.

Lebanon has long been a main front in what many see as a zero-sum power struggle between two main camps in the Mideast - the U.S. and its moderate Arab allies Saudi Arabia and Egypt on one side, and Iran and Syria and militant groups like Hezbollah and the Palestinian Hamas on the other. So any change in Lebanon’s delicate political balance will resonate beyond its borders.

Washington, which has given around $1 billion to Lebanon’s pro-Western government since 2006, has warned it could reconsider aid depending on the election’s outcome. Vice President Joe Biden delivered that warning when he visited the country last month.

Neighboring Israel has also raised the alarm. Vice Prime Minister Silvan Shalom called a win by Hezbollah, which fought the Jewish state in a 2006 war, "very dangerous for the stability of the Middle East, and by that the stability of the entire world."

Hezbollah has tried to strike a moderate tone in the election campaign, in part to ease concerns of Christians who will likely play a decisive role in the vote. It promises to invite its pro-Western opponents to join a national unity government if it wins.

The proposal shows Hezbollah’s concern over a punishing international backlash if it tries to govern Lebanon outright - as happened when the Iranian-backed Hamas won 2006 Palestinian elections, then violently took over the Gaza Strip. Hezbollah itself is only fielding 11 candidates.

The opposing coalition has hammered warnings that a Hezbollah victory will bring Iranian control in Lebanon, reinforce Hezbollah’s power as a virtual state-within-a-state and ensure it can keep its considerable arsenal of rockets that it used against Israel in the 2006 war. That resulted in massive retaliation and destruction.

Hezbollah officials maintain the guerrillas’ weapons are necessary to defend against Israeli attacks and an election loss would not necessarily weaken the group’s military strength. A defeated, embittered Hezbollah might also take a harder line.

The pro-Western coalition opposes Hezbollah keeping its arms and accuses Syria of continuing to interfere in Lebanese affairs and smuggling weapons to Hezbollah even though the two countries established diplomatic relations for the first time last year.