Key Points:

The Israeli operation is aimed not only at halting the firing of rockets into Israel but, even more ambitiously, to restore the armed forces' deterrent image which was dangerously bent out of shape in the war against Hizbollah in Lebanon in 2006.

Image is not a cosmetic issue in the Middle East but an existential issue, particularly for a country like Israel whose obliteration is overtly threatened by Iran and prayed for by many in the region.

The noted Beirut-based British correspondent for the Independent, Robert Fisk, referred to the Israel Defence Forces last week as "a pretty third-rate army" and Hizbollah leader Hassan Nasrallah has said that Israel was weaker than a "cobweb".

Such dismissive evaluations are based mainly on Israel's performance in the 2006 fighting, which it refers to as the Second Lebanese War, but also on its hasty withdrawal from Lebanon in 2000 and its failure to put an end to rocket fire from Gaza over eight years despite periodic incursions.

It was the IDF's performance on the battlefields of the 1967 Six Day War and the Yom Kippur War of 1973 that won it the grudging respect of its enemies who saw it as a power that could not be defeated. In the latter war, the Arabs caught Israel in a two-front battle with its reserves unmobilised. The IDF rallied and ended the war on the roads to Damascus and Cairo.

Israel's rescue of hijacked air passengers in Entebbe, Uganda, in 1976 and other commando operations added to its image. This eventually led to peace treaties with Egypt and Jordan, as well as diplomatic or informal contacts with other Muslim countries.

Israel found it more difficult subduing guerrillas, especially Hizbollah. With Hamas' seizure of control in the Gaza Strip, it became apparent that Israel was facing not just two tough local militias but the tentacles of a regional power, Iran, which was not only dedicated to Israel's destruction but moving towards development of nuclear weapons.

Israel did not regard itself as a paper tiger in the wake of the Second Lebanese War despite its missteps but it felt humbled. It also realised that the region was losing respect for its strength and that this could invite challenges. The reason for the war's errors were quickly assessed. The Army's principal operational duties for years had been focused on suppressing the Palestinian uprising and professional training had been neglected. Many reserve tank units had not trained in tanks for years, carrying out their reserve stints in policing duties on the West Bank or Gaza.

The chief of staff at the time was an Air Force pilot, General Dan Halutz, who had been appointed in the belief that Israel's principal strategic focus should be on a possible clash with Iran in which the Air Force would play the lead role. His performance in the war would be widely faulted by retired generals and within the Army.

Above all, the Israeli Government had rushed into the war within hours of an ambush on the Lebanese border without the ground forces being prepared. In the two years since then, the Army has trained intensively under a new chief of staff, Lieutenant General Gabi Ashkenazi, an infantryman, and the mistakes have been addressed.

Senior officers said that the Gaza operation would be "aggressive" and would use massive firepower. This clearly meant that the Army was prepared to inflict and take casualties.

In the previous few days, the IDF demonstrated that it was taking its gloves off by bombing an apartment of a senior Hamas leader even though his family was with him and by bombing mosques known to be Hamas control centres and rocket depots. In briefing the troops, officers stressed that the attack must be pressed without hesitation. The message was that what was at stake was not just rockets but Israel's image in the eyes of its enemies and its own

The desired image had been expressed by Israel's previous Air Force commander, General Eliezer Shkedy, when asked what message he would like to send to Iran. He replied: "Don't mess with us."