By Frank Gardner
BBC News, Jerusalem
The impact of more than 300 short-range missiles launched by Hezbollah this week has been felt well beyond the towns and olive groves of northern Israel.
After three weeks of an intensive Israeli air campaign in Lebanon, backed in recent days by about 10,000 Israeli troops on the ground, Hezbollah is demonstrating a remarkable resilience.
Small Katyusha rockets are easy to conceal
On Wednesday it sent a record number of missiles (231) into Israel, proving that despite the Israeli military's claims of success this Lebanese militia group remains a threat to northern Israel.
As long as that threat remains, Israel's military campaign in Lebanon - codenamed Miftza Shinui Kivun or Operation Change of Direction - will be perceived as a failure.
So how powerful is Hezbollah's arsenal of rockets and missiles and why, ask Israel's citizens, is it taking their military so long to neutralise them?
At the start of hostilities on 12 July Hezbollah had an estimated 13,000 missiles, amassed over the six years since Israel withdrew from Lebanon after its controversial 18-year occupation there.
The Israeli government says a large proportion of this arsenal has been destroyed but that may be wishful thinking on its part.
Most of these missiles are relatively crude Soviet-designed Katyushas with a range of 25km.
Although that restricts their target range to only the northernmost towns and villages in Israel they are having a psychological impact on Israelis since they say Hezbollah is packing them with ball bearings that can shred human tissue from some distance.
The Katyushas are easy to operate, easy to hide and easy to resupply.
Measuring less than two metres long, they can be concealed in orchards or, say the Israelis, among the civilian population in southern Lebanon.
Hezbollah's attack on an Israeli warship raised many questions
But their small size also means their explosive power is far smaller than that of a Scud missile or indeed of an air-to-ground missile.
An estimated 19 Israeli civilians have been killed to date while the Lebanese government says more than 900 of their citizens have been killed, many by Israeli airstrikes.
Hezbollah is also believed to have a smaller number of longer range Fajr-5 missiles with a range of up to 75km, long enough to hit the West Bank but not enough to hit Tel Aviv.
The only missile in Hezbollah's arsenal believed to be powerful enough to reach Israel's commercial capital is the Iranian-made Zelzal-2 with a range of 200km and a huge warhead of 400-600kg.
This large missile, which is about eight metres long, is effectively a strategic weapon and Israel has been at pains to destroy any suspected launch sites in Lebanon.
Some Israeli military analysts have said that if and when Hezbollah do fire such a weapon it would be a sign of desperation, a last-ditch blow against Israel before it sues for peace.
Hezbollah prides itself on being a Lebanese movement, but it also has strong connections to Iran.
Instructors from the Iranian Revolutionary Guards Corps (IRGC) have spent long periods in Lebanon, notably in the Bekaa Valley, teaching Hezbollah cadres how to use their weaponry.
Likewise, Hezbollah fighters have reportedly spent time in Iran undergoing military training.
One of the most effective weapons deployed by Hezbollah in this conflict has been the Iranian-made C-802 anti-ship missile. A variant of the Chinese Silkworm missile, one of these was successfully fired at an Israeli warship last month, killing four people onboard and severely damaging the vessel.
The Israeli military appears to have been taken by surprise by the attack and now believes that Iranian advisers from the IRGC were present at the launch of the missile.
One of Israel's major concerns, which has a bearing on the terms of any UN-brokered ceasefire agreement, is that once the fighting stops then Iran will replenish Hezbollah's arsenal of missiles via Damascus and the Syrian-Lebanese border.
So, Israel will likely insist on UN or international monitors being stationed along the 375km (233 mile) border.