Gaza. Always the suffering of Gaza, most potent symbol of the tragedy of Palestine. In 1948, during the Nakba – or "The Catastrophe" as Palestinians describe the war that gave birth to the state of Israel – 200,000 refugees poured into Gaza, swelling its population by more than two-thirds. Then Gaza fell under Egyptian control.

The six day war of 1967 saw more refugees, but with it came the occupation of Gaza by Israel – an occupation that, despite Israel's declaration under Prime Minister Ariel Sharon that it would unilaterally withdraw its settlements and troops in 2005, has never really ended.

It has not ended, for to be in Gaza is to be trapped. Without future or hope, limited to a few square miles. Its borders, land and sea, are defined largely by Israel (with Egypt's compliance along the southern end of the Strip).

It is not open to the ocean apart from a narrow outlet accessible only to the fishing fleet, a coastal blockade policed by Israel's gunboats, the boundaries of which have only recently been tested by boats of protesters sailing from Cyprus to draw attention to conditions inside Gaza.

Once it was possible for Gazans to pass with relative ease in and out of the Strip to work in Israel. In recent years, the noose around the 1.5 million people living there has been tightening incrementally, until a whole population – in the most densely settled urban area upon the planet – has been locked in behind walls and fences.

Since Israeli troops overran the Strip in 1967, Israeli politicians and generals have always seen it as a problem – a hotbed of radicalism and opposition. And so Israel has ventured failed experiment after experiment in the attempt to control Gaza. It has tried everything except the obvious – to allow its people to be free.

It has tried directly managing Gaza, and a brutal policy of quarantine backed by tanks, jets and gunboats. It has attempted the maintenance of strategic settlements, which only provided a focus for resistance against the patrolling troops. And when that failed, Israel retreated – only to find that, without a proximate enemy, those living inside turned to attacking the nearby towns with crude missiles.

Ironically, one of Israel's experiments involved assisting in the creation of Hamas, which had its roots in Egypt's Muslim Brotherhood, to counter the power of Yasser Arafat's Palestine Liberation Organisation. Israel has been determined to push Hamas ever closer to all-out war since insisting that even though it won free and fair Palestinian legislative elections in 2006, its right to govern could not be treated as legitimate.

Since Hamas took power in Gaza in summer 2007, after a short, brutal struggle with Fatah, Israel's policy has been one of collective punishment, summed up in the policy of "no prosperity, no development, no humanitarian crisis". Not a visible humanitarian crisis, at least.

For what has been going on inside Gaza since the economic blockade began a year and a half ago has cynically stretched the definition of what constitutes the boundaries of such a crisis.

Those seeking urgent medical care outside Gaza's walls are forced to go through a long and humiliating process. Even some of those who are allowed to leave, human rights groups say, have been pressured into becoming informers for Israeli intelligence.

One in two Gazans is now living in poverty. Aid is sporadic, and as the World Bank warned at the beginning of December, the blockade has forced Gaza to become reliant on smuggling tunnels (taxed by Hamas), which risked destroying its conventional economy. Inflation for key products smuggled through the tunnels is rampant, which in turn has brought cash to Hamas.

Equally worrying, from a long-term point of view, has been the corrosion of Gaza's institutions and social cohesion, which has resulted in sporadic eruptions of inter-factional and inter-clan violence.

What Israel hopes to achieve with the present military offensive – beyond influencing the coming Israeli elections – is not clear. For if a long-anticipated ground operation, leading to a partial reoccupation on the ground, is to follow these air strikes – as it did in the war in Lebanon in 2006 – it will have to achieve what neither Hamas nor its rival Fatah can: unifying Palestinian society once more against a common enemy, as Gaza was once united against Israeli settlements inside its boundaries.

If that is not the intention, it is hard to see what Israel's actions are meant to achieve in a community that cherishes its martyrs; where violent death is intended to reinforce social cohesion and unity.

For in the end what has happened in the past few hours is simply an expression of what has been going on for days and months and years: the death and fear that Gaza's gunmen and rocket teams and bombers have inflicted upon Israel have been returned 10, 20, 30 times over once again. And nothing will change in the arithmetic of it.

Not in Gaza. But perhaps in a wider Arab world, becoming more uncomfortable by the day about what is happening inside Gaza, something is changing. And Israel has supplied a rallying point. Something tangible and brutal that gives the critics of its actions in Gaza – who say it has a policy of collective punishment backed by disproportionate and excessive force – something to focus on.

Something to be ranked with Deir Yassin. With the Sabra and Shatila massacres. Something, at last, that Israel's foes can say looks like an atrocity.