There are two Israeli explanations for why this is happening. When the Israeli navy first started stopping fishing boats on 8 February, officials in Jerusalem said the measure was in retaliation for the Lebanese government's harassment of Lebanese living in Israel's ``security zone'' in southern Lebanon, whenever they travelled north into government-controlled territory.
But yesterday, the Israeli Foreign Minister, Shimon Peres, denied this. "There is no blockade," he said. Boats were being stopped to search for arms. The naval action had nothing to do with the security zone. The reason was purely military.
The Israeli action is making the Lebanese government nervous. The blockade, as Israeli comentators describe it, started with a ban on ships leaving or entering the port of Tyre. It was extended up the coast to cover Sidon and Damour, forcing the Lebanese government this week to distribute relief to the worst affected of the 10,000 Lebanese who depend on fishing.
It may be that Israel originally intended to give aid and comfort to the South Lebanon Army, the Israeli-controlled militia under General Antoine Lahd which has been battered recently by pro-Iranian Hizbollah guerrillas.
Israeli officials also admit the militia's morale is low because of fears that, after a peace settlement between Israel and Lebanon and Israeli withdrawal, its members would be hunted down as collaborators.
But the blockade is only one aspect of a more aggressive stance by Israel in southern Lebanon. Last week, the Israeli Prime Minister, Yitzhak Rabin, visited the area. The Israeli army is making more pre-emptive strikes against Hizbollah. In Beirut, commentators wonder for how much longer the US-brokered understanding of 1993 - when Hizbollah stopped firing Katyusha rockets into Israel in return for an Israeli promise not to attack civilian targets - will last.
The Israeli action is also probably geared to a planned visit by the US Secretary of State, Warren Christopher, to the Middle East next Wednesday.
The visit is considered a last chance for an Israeli-Syrian agreement before the 1996 elections in the United States and Israel. By underlining that Syria, the dominant power in Lebanon, cannot stop Israel doing what it wants, Israel may hope to put extra pressure on Damascus to make concessions.
The Israelis are unlikely to succeed. President Hafez al-Assad of Syria made a defiant speech last weekend, pledging to support those who ``in self-defence fight with flesh and bone and stone and knife.'' He is reported to be doubtful that Mr Rabin, his standing badly bruised by suicide bomb attacks, could risk further unpopularity by withdrawing from the Golan Heights.
Despite Mr Peres's rejection of the term, Israel is in fact carrying out not one but two blockades. The first is against the Lebanese coast and the second is against the Gaza strip and the West Bank, where most Palestinians are banned from travelling to work in Israel.
Both blockades create friction but are probably Israel's most effective way of maximising pressure on Syria, Lebanon and the PLO, without firing a shot.Reuse content