Both belligerentsuse weapons for maximum terror and casualties

The missiles currently being fired by Hizbullah into Israel vary in calibre and range. The most commonly fired Hizbullah missile is the Katyusha rocket, or its Iranian variant, the Fajr-3. With a range of approximately 40km, this missile delivers a warhead of 22kg of high explosives on to civilian targets.

The Fajr-3 is an indiscriminate weapon with no guidance systems to speak of. Originally designed to achieve "area suppression" on the conventional battlefield, it is launched in multiples on a simple compass bearing in the direction of the target.

As such it is especially lethal when fired at high-density population centres such as the northern Israeli towns of Netanya or Nahariya.

It is suspected that Hizbullah has also fired a number of Iranian Fajr-5 rockets at Haifa and Nazareth. These weapons can carry a warhead of approximately 50kg to 70kg of high explosives.

With more than 40 missile attacks per day, a rough estimate might conclude that Hizbullah is delivering more than 1,000 kgs of high explosives on to Israeli civilian targets on a daily basis. One kilogram of high explosives would be sufficient to cause the carnage experienced by Spanish and British civilians in the London and Madrid bombings.

Hizbullah's strategy would appear to be one of the deliberate and indiscriminate targeting of civilian population centres in order to achieve maximum casualties and terror.

Israel's response has been equally indiscriminate, but of a far higher quantum. The 155mm and 175mm artillery barrages being fired by the Israeli Defence Forces (IDF) along the Lebanese border are particularly devastating for Lebanon's small villages and refugees.

Each IDF artillery unit consists of at least six US-designed M107-type self-propelled artillery pieces. Each weapon routinely fires at what the military refers to as "rate six" - or six 175mm rounds per minute.

With a 175mm shell weighing over 40kg - 24kg of which is a high explosives warhead - this means that a single Israeli artillery unit is capable of delivering up to 1,000kg of high explosives ordnance - per minute - on to Lebanese towns and villages.

Up to a dozen such IDF artillery units are constantly engaged in hours of bombardment in south Lebanon. This means that from ground artillery alone, the IDF are responding to pinprick attacks from Hizbullah with a barrage of many hundreds of thousands of tons of high explosives directed among the Lebanese civilian population.

Each of these artillery rounds has a lethal radius of approximately 250 metres from the point of detonation to include blast and shrapnel effect. The IDF routinely use delayed fuse settings and white phosphorous shells to increase the lethal effect of such barrages - with the artillery rounds literally boring into houses using kinetic energy and then exploding, shattering and burning those taking shelter there. With the elderly and nursing mothers least likely to be in a position to flee such barrages, it is no surprise to learn that a high proportion of Israel's victims thus far are children.

Added to this daily tally are the 500kg and 1,000kg bombs being fired at Lebanese targets from wave after wave of Israeli F-16 jets - not to mention the tonnage of ordnance being fired at Lebanon's cities from Israeli warships.

These crude figures and calculations do not adequately measure the human misery and horror currently unfolding in Lebanon. From a strictly objective, military point of view, however, Israel's response to Hizbullah's terror attacks appears grossly disproportionate and bears the hallmarks of a campaign of state terrorism. Not only should the international community call an immediate halt to the current exchange, it should also contemplate a subsequent vigorous investigation into war crimes by both belligerent parties.

•Dr Tom Clonan is The Irish Times security analyst. He lectures in the School of Media DIT.