The Lebanon War
This is a direct result of the disfunctionality of the Lebanese government.The Lebanese system of government is legacy of French colonial rule (a bad start in life), that originally gerrymandered the Muslims away from power and favored the Maronites. Forever locking the Muslims (Shia and Sunni) out of power proved to be a problem. A sectarian war lasting 15 years is the most significant event of Lebanon's post colonial history. This resulted in a marginal reweighting of the gerrymander to favor both the Sunni and the Maronite minorities over the Shia. Unfortunately for the Sunni and the Maronites the war also resulted in the Syrian takeover of 90% of Lebanon, to go with the 10% Israel had taken during the war.
The Syrians brought a new perspective to Lebanon - they were in charge. Everybody else were left to get by and manage the country's affairs using the same parliamentary system, but Syrian patronage was available to any that could advance Syrian interests. Syria was largely interested in hurting Israel (a country that occupies some of Syria) and hence Hezbollah & Amal (the Shiite parties) were sponsored. Iran also offered patronage to it's co-religionists, favoring the Islamist Hezbollah over the more secular Amal.
This brought money and services from foreign wealth to the Shia people, the poorest of the Lebanese sects. This had an immediate effect of making them popular. Popularity was strengthened when they beat Israel out of southern Lebanon.
Then Lebanon changed again with the Cedar Revolution of last year. The Syrians withdrew their military under American pressure, their sponsorship was reduced and elections were held. The elections were held under the same stupid, gerrymandered system that had always excluded the Shia. The Maronites and Sunni were grasping for power, but Hezbollah was still armed. The only choices for the Shia were to follow Hezbollah (Amal was closer to Syria & weakened more by Syrian withdrawl) or to be subservient to the Sunni & Maronites.
To have any chance at peace Shia need another choice. They need to be able to gain power without guns, this requires democracy (in all its majority rule ugliness) be brought to Lebanon. If the Shia are able to share in the prosperity of Lebanon they will be more inclined to want a peaceful Lebanon.
Update 18/08/06:
There is a lull in the conflict, ceasefire in place. The UN and Lebanon government are taking charge. Let us hope that the Lebanese are able to offer the Shia a path into a free and democratic Lebanon. This could be the last chance for an equitable peace. Good luck to everybody.