Dramatic news reports, claims and videos have emerged from both sides involved in the Gaza fighting throughout the past week.

The week started with the Israeli army releasing several videos of Palestinians stripped to their underwear being marched through urban ruins. Israel’s PR machine disregarded the Palestinian outcry that followed. Israel staunchly asserted that the men were Hamas fighters and that their alleged mass surrenders signified that the end of the Palestinian group was close, even as many Palestinians and independent observers insisted that the men were civilians who had been treated against the laws of war by being publicly humiliated.

For its part, Hamas stuck to its usual practice of pushing its cause through video releases – skilfully edited to enhance the desired effects – purporting to confirm its constant and numerous successes against Israeli invaders, mostly showing hits scored against armoured vehicles.

Then came the news that stunned Israel and put a big question mark on its official line of Hamas being on the verge of collapse. First, nine soldiers were killed in a single operation in the Shujaiya neighbourhood of Gaza City on Tuesday. That shock was followed by another one on Friday, with the Israeli army admitting that it killed three Israeli captives, having mistaken them for enemies – even though they held white flags.

So what is really happening on the ground in Gaza?

Nothing we did not predict weeks ago: The war has entered a difficult, unpredictable and bloody phase of full-scale urban warfare where gains are small and slow, and losses can be huge.

Combat in narrow and cramped streets of old cities is known to be one of the most difficult ways to fight a war. Classic military theory calls for defended cities to be surrounded and blockaded by units just strong enough to prevent the defenders from breaking out, while the main force continues advancing and taking territory.

But the fight in Gaza is not about conquering fields and beaches – Israel’s proclaimed goal is to destroy Hamas. To do that, the first step is to control the ground where the enemy operates: the cities.

In the old days, cities needed strong walls to defend themselves, but in the last 100 years, weapons have advanced at a rapid rate, causing a change in tactics. Successful resistance against enemy attacks no longer depends on huge, expensive static bastions. Nowadays, small but potent man-portable weapons whose destructive power is hugely disproportionate to their size, such as anti-tank rocket launchers, grenade throwers, small mortars, assault rifles and many others, allow the defenders to turn each house and every street into a formidable defensive position.

In their own ways, Stalingrad, Warsaw, Berlin, Dien Bien Phu, Vukovar, Sarajevo, Grozny and Fallujah – some successfully defended, others eventually succumbing to attacks – all confirmed the military wisdom that urban warfare should be avoided whenever possible.

Israel could not avoid urban warfare in Gaza. To have a chance of destroying Hamas, it has to deny it its operating ground, the three biggest urban agglomerations in the strip: Gaza City, Khan Younis and Rafah.

The second phase started with Israeli forces reaching the suburbs, first of Gaza City and then, after the temporary ceasefire expired, of Khan Younis. Treading slowly and carefully in expectation of a concentrated Hamas response, the Israeli military completed the encirclement of those two urban areas.

It would be naive to assume that Israel’s generals hoped that by isolating the two biggest built-up areas in the Gaza Strip, they would seriously impair the ability of the Qassam Brigades, Hamas’s armed wing, to fight back.

In reality, the encirclement of the two city centres is not a classic one where troops within the blockade cannot be reinforced nor receive any supplies. Hamas still has an unknown but probably major part of its tunnel network intact and can move in and out. They have some difficulties in doing so but Hamas fighters are not locked in.

Aware of the menace that tunnels present but also of the grave hazard of taking the fight into them, Israel has tried several approaches. It has destroyed as many tunnel entrances as it has found, mostly in the areas under its control, but many others that remain keep the danger acute.

After several attempts to send troops underground that ended in disaster, with troops falling casualty to Hamas booby traps, the high command abandoned that approach. It then reportedly mulled the idea of filling tunnels with seawater, claiming that the test-flooding was successful but it has not yet decided to mount a full-scale deluge operation.

This week’s Israeli actions on the ground strongly suggest that the Israeli army leadership realises that the only way towards achieving its proclaimed goal of annihilating Hamas is by taking, holding and controlling the ground throughout the currently surrounded centres of Gaza City and Khan Younis.

That in itself would not guarantee victory but could create conditions to squeeze Hamas fighters into tunnels, after which Israeli forces could block and destroy all entrances.

Flushing Hamas out would probably take weeks of heavy urban warfare with many more instances of massive losses – on both sides.

The more Israeli soldiers get killed in inner cities of Gaza, without still being able to claim the destruction of Hamas, the more the support for the continuation of the military operation would ebb. At some point, calls from Israel to stop the war could become louder than those encouraging it to continue.