One Israeli citizen was killed and several wounded in a Hizb Allah shelling on Sunday. The Lebanese Muslim resistance group claims it was an anti-aircraft shell that went astray.
The Israeli military said it was a targeted attack and swiftly responded with air strikes on a Lebanese border village.
In the storm of claims and counter-claims, attacks and counter-attacks, it seems the region is about to tip back into the messy conflict that raged for over 20 years from Israel’s invasion and occupation of Lebanon in 1978, until its withdrawal three years ago.
Israeli soldiers finally pulled out of occupied territories along the Israel/Lebanon border in May 2000. Then Prime Minister Ehud Barak declared “the tragedy is over”. But his confidence belied the fact that all of the actors in the long-running border dispute had unfinished business.
1943 - Lebanese independence from France
1963 - Israel occupies Golan Heights in Syria
1975-1990 - Civil war in Lebanon. Israel, Syria and PLO all involved
1982 - Israeli invasion, occupation of Beirut
1985 - Israel pulls back to southern 'security zone'
2000 - Israel withdraws troops, except from Sebaa Farms area
2003 - Border skirmishes escalate
Hizb Allah, which now controls south Lebanon with Iran and Syria’s backing, claimed victory, but has continued to demand the release of Lebanese prisoners and Israel’s withdrawal from the Shebaa Farms area, close to the poorly-defined border of Lebanon and Syria.
This tiny patch of land, little more than 10 square kilometres, has emerged as the new flashpoint for conflict between Israel and Hizb Allah.
Israel claims most of the area lies on the Syrian side of the Lebanon/Syria border and that it will only withdraw from the part marked as Lebanese territory on United Nations maps.
The 14 farms are named after the village of Shebaa, on the western slopes of Mount Hermon. They are located to the south of the village, at altitudes ranging from 400 to 2,000 metres.
No-one disputes that the village of Shebaa itself is in Lebanon, but most of the farms fall into an undefined area that may be either in Lebanon or Syria.
Kofi Annan says border is too vague
Syria agrees with Lebanon that the Shebaa farms area is part of Lebanon. However, Israel claims that Syria does not have the right to cede the land, since Israel seized the territory from Syria during the 1967 Middle East War.
The UN Secretary-General Kofi Annan wrote in a report to the Security Council this week that the border was vague. "There seems to be no official record of an international boundary agreement between Lebanon and Syria that could easily establish the line for purposes of confirming the withdrawal," he said.
Mr Annan proposed that all sides should adopt the line drawn after the 1974 Yom Kippur war, pending a permanent delineation of the border.
Syria maintains presence
Syria still has 15,000 soldiers in the country, mostly near Beirut, in the north, and in the eastern Bekaa Valley. The presence is down from about 35,000 three years ago.
Lebanese newspapers have reported that all Syrian troops could be withdrawn from Lebanon by next year, but further Israeli military action could reverse this process.
In any event, Syria is likely to continue to support Hizb Allah as a proxy in its struggle against Israel.
Some analysts say that peace between Hizb Allah and Israel would not be in Syria's interests, because Syria does not want to see Israel's border secure until Israeli troops withdraw from the Syrian Golan Heights mountain range it has occupied since 1967.
South Lebanon remains torn between regional powers at odds with one another, as it has for the past quarter century. Unless the borders with Israel and Syria are drawn to all parties’ satisfaction, which seems almost impossible, the hard won and fragile peace looks set to unravel.