“It’s not a pleasant sight,” the brigade commander conceded, and he was right. The Gaza Strip was always grim, but 20 days after the Israeli military unleashed its firepower on that narrow sliver of Palestinian territory, it looks – and sounds – like Armageddon.

Under pressure, the Israelis yesterday allowed in the first small group of foreign journalists since the war began. We were not taken far, only to the edge of al-Atatra, a town from whose environs Hamas regularly fired rockets into southern Israel a few miles north. It has paid a terrible price.

The houses and ugly concrete apartment blocks have been abandoned and mostly reduced to shells, their walls pockmarked by shrapnel. The commercial greenhouses have been crushed. The metal roof of what used to be a factory or warehouse has been sent crashing to the ground.

The vegetable fields have been churned up by tanks and bulldozers. There is not a Palestinian to be seen – just the odd scarecrow standing forlornly in the midst of their ruined crops. An empty casino and the odd palm tree overlook a deserted beach and the deep-blue Mediterranean.

It is scarcely surprising that the civilians have fled. This is no longer a place where anyone would want to linger. The air reverberates with the crump of exploding shells and the crackle of automatic gunfire. Tanks and giant bulldozers – their cabins caged in steel to block rocket-propelled grenades – roar past, throwing up clouds of dust behind them.

Great banks of smoke billow up from bomb sites amid long, low rows of distant buildings, casting a pall across the sun and sky. This area now appears largely to be secured, but we still cannot go too close for fear of snipers or booby-traps. The only people in sight are Israeli soldiers flourishing their automatic weapons.

It was a stunning contrast to the peaceful citrus orchards, the neat fields of vivid green spring wheat, and the orderly rows of hothouses of southern Israel that we had left behind 20 minutes earlier. But Colonel Herzi, the commander, and his fellow paratroops are not afflicted by doubts about the justice of their mission, or about their overwhelming use of force. If they are aware of the international condemnation of Operation Cast Lead, they do not let it trouble them.

Hamas brought this death and destruction on itself, they argue with manifest passion. By continuing to rain rockets on Israel, it left them with no alternative. “I don’t like seeing these ruined houses,” Colonel Herzi said, “but they didn’t give us any choice except to fight and show them that they should stop and find another way to live with us.”

He recalled the Israeli withdrawal from al-Atatra and other Gazan settlements in 2005. “Three years ago they had a wonderful chance to create with us industry, agricultural areas,” he said. “We left this place in very good condition. But they chose to go in a different way and so we had to fight.”

Avi Ronzki, a uniformed army rabbi with a long grey beard, agreed. “It’s a very righteous war,” he said. “Our army is showing that to beat terror you need to use a lot of force like the Americans in Iraq or Afghanistan.”

The soldiers did not want to stop now, the rabbi added. “They want to destroy Hamas. If you leave even a small core it will rise again, so it should be snuffed out entirely.”

Another senior officer insisted that the Israelis were striving to minimise civilian casualties – even telephoning houses before shelling them to tell the occupants to leave. It had to do this, he said, because Hamas was using civilians as human shields.

Colonel Herzi was contemptuous of Hamas. He claimed that it had booby-trapped one third of the houses, left a bomb concealed in a Unicef bag, and chiselled explosives into the walls of a mosque so that its men could bring the entire building tumbling down when Israeli soldiers entered.

He claimed that the soldiers faced daily suicide attacks, many by women, though when pressed he admitted that only two had got close to his men. He said that on Wednesday two Hamas fighters had shot at an Israeli post, retreated into a house, and had blown it up when the Israelis followed, trapping an officer beneath the rubble. He also said that Hamas was using the daily three-hour truce for the distribution of humanitarian aid to rearm.

None of these claims can be verified, but the colonel did display photographs of various guns, explosive devices, rockets and tunnels that his men had discovered. A few of his men had been wounded, and one who had got married a day before the operation began was now critically injured. In the face of such challenges, he said, “you have to use power . . . we have an enemy that doesn’t know any law”.

He insisted that the Israelis were winning. Hamas had been shocked by the ferocity of the offensive. Its fighters were demoralised. They were engaging only at long range. “They still fight on, but not in a strong way.”

But Colonel Herzi is a veteran who believes that Israel’s battle for survival is never finished. Indeed, his command includes Unit 101, which Ariel Sharon, the hawkish former Israeli Prime Minister, set up at David Ben-Gurion’s request more than half a century ago to stamp out Beduin attacks from the Gaza Strip.

The aim of the offensive, he said, was to teach Hamas such a harsh lesson that it would never provoke Israel again. But he added: “I don’t think this war will bring peace. It’s part of a long process. Because that’s the way they choose to deal with us it’s very important that we win every battle against them . . . Will they leave their weapons for ever? I know for sure the answer is no.”

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