Lebanese head to the polls Sunday in crucial parliamentary elections that could determine the country's future for the next four years. Here's what to look for as voting begins: ___ Q: Who are the major players? A: On one side, a coalition of pro-US and pro-Western factions. On the other, the pro-Iranian and pro-Syrian Hizbullah and its ally, Christian leader Michel Aoun. Sunni Muslims overwhelmingly support the former, Shiites the latter - and Christians are divided between them. That makes Christians the swing vote. Independent Christian candidates may also win enough seats to deny either side an absolute majority. Q: What does a victory by the Hizbullah alliance mean? A: An election win for Hizbullah and its allies would propel the Shiite militant group, which the United States considers a terrorist organization, to a position where it would have a major say in the formation of Lebanon's next government. This in turn could present a setback for the Obama administration as it tries to start up dialogue and resume peace talks in the Middle East. Israel is also alarmed, having fought the heavily armed Hizbullah but failing to defeat it in a 2006 war. Q: What happens if the current ruling coalition retains its majority? A: The majority may try to form a government excluding Hizbullah, which would leave the influential group in the opposition. But it will likely be unable to do that and will have to form another unity government, including Hizbullah. Hezbollah and its allies have had veto power over major Cabinet decisions since July 2008. Q: What are the major issues? A: - Huzbullah's weapons: The pro-Western coalition opposes Hizbullah keeping its arms, but Hizbullah and its allies maintain those weapons are necessary to defend against Israeli attacks. - Relations with Syria: Syria, which controlled Lebanon for almost three decades before it pulled out its troops in 2005, has established diplomatic relations with Lebanon. But officials in the pro-Western coalition accuse Syria of continuing to meddle in Lebanon and of smuggling weapons to Hizbullah. The pro-Western coalition says a win by Huzbullah would increase Syrian and Iranian influence in Lebanon. - The UN tribunal set up to try the killers of former Prime Minister Rafik Hariri: His supporters blamed the murder on Syria, although Damascus denied involvement. Q: What is likely to be the international reaction in case of a Hizbullah victory? A: Washington has warned it could reconsider its aid to Lebanon, and neighboring Israel called a possible win by Hezbollah a danger to the stability of the Middle East and the world. But some analysts say the international community is likely to deal with any future Lebanese government regardless of the election winners.