The confrontation between Israel and Hezbollah is clearly unbalanced. Israel is a significant military power with sophisticated land, sea and air forces at its disposal.
By Jonathan Marcus
BBC diplomatic correspondent
Hezbollah rocket attacks on Israel have multiplied
Hezbollah began as a guerrilla force but over the years it has evolved a complex military infrastructure. Nonetheless it has few of the types of weapons available to the Israelis. Its only long-range punch comes from an assorted arsenal of missiles.
Most of these are relatively short-range systems, generically known as Katyushas, capable of striking targets out to about 25km (16 miles).
But the Hezbollah missile strikes on Israel's northern port city of Haifa demonstrate that it also has an unknown quantity of longer-range systems in its arsenal.
Most of these are Iranian-manufactured systems like the Fajr-3, with a 45-km range; the Fajr-5, with a range of some 75km; and the more potent Zelzal-2 with a range of up to 200km.
This would bring much of Tel Aviv - Israel's largest population centre - within range.
None of these are guided or accurate systems but if the target is an urban area, accuracy is not needed.
In addition, as the successful attack on an Israeli naval vessel demonstrates (an Egyptian freighter was also hit and abandoned by its crew), Hezbollah also has relatively sophisticated Iranian-supplied anti-shipping missiles at its disposal.
Air war limitations
This missile build-up has worried the Israeli military for some time.
Israeli strategists know an air war has its limits
No surprise then that Israeli leaders have taken the opportunity of the Hezbollah raid which captured two of their men, to set about the full-scale weakening of Hezbollah's infrastructure.
Headquarters, television stations, and missile storage bunkers have all been hit.
But the Israelis have also sought to blockade Lebanon - closing Beirut's airport, striking the Beirut-Damascus highway, and hitting various key transport links, especially bridges.
The Israelis explain all this by saying that they are acting to prevent Hezbollah bringing in or moving up additional missiles to the border. Inevitably, such attacks, however precise, cause civilian casualties.
Israel's long-term goals are obvious. It wants to end the cross-border missile threat to its towns and cities by applying a blunt lesson in deterrence.
It would like to see Hezbollah disarm and the Lebanese Army extend its control down to the international frontier. That is what UN Security Council Resolution 1559, of 2004, also demands - but it is hard to see how it can be enacted.
Israel's tactics are to some extent puzzling. The bludgeoning of Lebanon's transport infrastructure will hinder, but will probably not stop, missile movements.
Indeed, Hezbollah has shown remarkable resilience, and the rockets are still flying across Israel's northern border. It is very hard to deliver a body blow to Hezbollah from the air.
So is this all a prelude to some significant Israeli incursion on the ground?
On the face of things Israel has not yet mobilised sufficient troops for such an operation. And a comprehensive assault on Hezbollah would require a move into the strategically important Bekaa Valley, a step that would send alarm bells ringing in Syria, risking an even wider confrontation.
Dangers of complacency
Israel's own military performance raises several questions.
A deadly missile attack on one of its warships shocked Israel
Even Israeli commentators have pointed to the fact that the capture of Israeli soldiers, first by Palestinian militants and now Hezbollah, shows clear signs of laxness and a lack of vigilance on the part of the reserve units involved.
Hezbollah has clearly signalled its desire to carry out such operations and it has attempted similar things in the past. Has reserve training been reduced too far? Has a certain complacency set in?
The attack on the Israeli missile boat - one of its most sophisticated warships, a Saar-5 class corvette - also raises many questions.
It was hit by a Chinese-made, radar-guided C-802 missile.
Did Israeli intelligence not know that these anti-shipping missiles had been given to Hezbollah by Iran?
Israel's naval electronics and defensive systems are among the best in the world, defensive systems intended to counter just such a threat. Some reports suggest that they were not even operating on board the vessel that was hit.
But most of all there is the question of the new Israeli government's relationship with the military.
Much has been made of the limited military experience of Prime Minister Ehud Olmert and Defence Minister Amir Peretz.
Mr Olmert is in a tight spot. He has to act to protect Israel's citizens. But ask a general what action can be taken in response to a threat and he will generally supply a long list of targets.
Israel seems to be working through just such a list. But the real strategic calculation is to weigh up military advantage against wider political and diplomatic considerations.
Has Israel got the balance right?
Clearly there are many views. But the overwhelming international consensus - not least from the G8 summit in St Petersburg - is that disproportionate military force has been used.
President George W Bush - who has strongly backed Israeli action - nonetheless put this point rather neatly.
"Defend yourself," he said, "but be mindful of the consequences."