WITH luck, the destructive two-week battle between Israel and Hamas may soon draw to an end. But how long before the century-long war between Arabs and Jews in Palestine follows suit? It is hard to believe that this will happen any time soon. Consider: Israel’s current operation, “Cast Lead”, marks the fourth time Israel has fought its way into Gaza. It almost captured Gaza (behind a pocket containing a young Egyptian army officer called Gamal Abdul Nasser) in 1948, in the war Israelis know as their war of independence. It captured Gaza again in 1956, as part of a secret plan hatched with Britain and France to topple Nasser as Egypt’s president and restore British control of the Suez Canal. It invaded a third time during the six-day war of 1967—and stayed there for 38 years, until withdrawing unilaterally three and a half years ago.

Why they fight

And Gaza, remember, is only one item in a mighty catalogue of misery, whose entries are inscribed in tears. The Jews and Arabs of Palestine have been fighting off and on for 100 years. In 1909 the mostly Russian socialist idealists of the Zionist movement set up an armed group, Hashomer, to protect their new farms and villages in Palestine from Arab marauders. Since then has come the dismal march of wars—1948, 1956, 1967, 1973, 1982, 2006 and now 2009—each seared by blood and fire into the conflicting myths and memories of the two sides. The intervals between the wars have not been filled by peace but by bombs, raids, uprisings and atrocities. Israeli settlers in Hebron today still cite, as if it were yesterday, the massacre of Hebron’s Jews in 1929. The Arabs of Palestine still remember their desperate revolt in the 1930s against the British mandate and Jewish immigration from Europe, and the massacres of 1948.

The slaughter this week in Gaza, in which on one day alone some 40 civilians, many children, were killed in a single salvo of Israeli shells, will pour fresh poison into the brimming well of hate (see article). But a conflict that has lasted 100 years is not susceptible to easy solutions or glib judgments. Those who choose to reduce it to the “terrorism” of one side or the “colonialism” of the other are just stroking their own prejudices. At heart, this is a struggle of two peoples for the same patch of land. It is not the sort of dispute in which enemies push back and forth over a line until they grow tired. It is much less tractable than that, because it is also about the periodic claim of each side that the other is not a people at all—at least not a people deserving sovereign statehood in the Middle East.

That is one reason why this conflict grinds on remorselessly from decade to decade. During eruptions of violence, the mantra of diplomats and editorialists is the need for a two-state solution. It sounds so simple: if two peoples cannot share the land, they must divide it. This seemed obvious to some outsiders even before the Nazi genocide of Europe’s Jews prompted the United Nations in 1947 to call for the creation of separate Jewish and Arab states in Palestine. In 1937 a British royal commission concluded that “an irrepressible conflict has arisen between two national communities within the narrow bounds of one small country.” The answer had to be partition.

The fact that the Arabs rejected the UN’s partition plan of 60 years ago has long given ideological comfort to Israel and its supporters. Abba Eban, an Israeli foreign minister, quipped that the Palestinians “never missed an opportunity to miss an opportunity”. Israel’s story is that the Arabs have muffed at least four chances to have a Palestinian state. They could have said yes to partition in 1947. They could have made peace after the war of 1947-48. They had another chance after Israel routed its neighbours in 1967 (“We are just waiting for a telephone call,” said Moshe Dayan, Israel’s hero of that war). They had yet another in 2000 when Ehud Barak, now Israel’s defence minister and then its prime minister, offered the Palestinians a state at Bill Clinton’s fateful summit at Camp David.

This story of Israeli acceptance and Arab rejection is not just a yarn convenient to Israel’s supporters. It is worth remembering that it was not until 1988, a full 40 years after Israel’s birth, that Yasser Arafat’s Palestine Liberation Organisation (PLO) renounced its goal of liberating the whole of Palestine from the river to the sea. All the same, the truth is much more shaded than the Israeli account allows. There have been missed opportunities, and long periods of rejection, on Israel’s part, too.

Look again at those missed opportunities. At the time of the UN partition resolution, the Jews of Palestine numbered only 600,000 and the Arabs more than twice that number. Most of the Jews were incomers. Although partition might have been the wiser choice for the Palestinians, it did not strike them as remotely fair. In the subsequent war, more than 600,000 of Palestine’s Arabs fled or were put to flight. Afterwards, disinclined either to take them back or return the extra land it had gained in battle, Israel was relieved that the Arab states, traumatised by the rout, made no serious offer of peace. Many of the refugees have been stuck ever since in a sad finger of dunes, the Gaza Strip, pointing at the bright lights of Tel Aviv.

When Israel fell in love

After the ignominious defeat of 1967, the Arab states again rejected the idea of peace with Israel. That was, indeed, a wasted opportunity. But even though the Israel of 1967 discussed how much of the West Bank it was ready to trade for peace, the Likud governments of the late 1970s and 1980s wanted it all. For Israel fell in love with the territories it had occupied.

This was the period of Israeli rejection. Israeli prime ministers such as Menachem Begin and Yitzhak Shamir asserted a God-given right to a “greater Israel” that included the West Bank and Gaza Strip, in which Israeli governments of all stripes continued to plant (illegal) settlements. In some Israeli minds the Palestinians became a non-people, to be fobbed off with self-government under Israeli or perhaps Jordanian supervision. It took an explosion of Palestinian resistance, in the intifada (uprising) of the late 1980s and the far more lethal one of 2001-03, to convince Israel that this was an illusion.

What bearing does all this history have on the foul events unfolding right now in Gaza? The point is that there have been precious few moments over the past century during which both sides have embraced the idea of two states at the same time. The most promising moment of all came at the beginning of this decade, with Mr Clinton’s near-miss at Camp David. But now, with the rise of Hamas and the war in Gaza, the brief period of relative hope is in danger of flickering out.

If rejection of the other side’s national claims is one of the things that make this conflict so hard to end, the other is religion. The two are tied together. Hamas is a religious movement, and its formal creed is to reject the possibility of Jewish statehood not only because of Israel’s alleged sins but also because there is no place for a Jewish state in a Muslim land.

In Israel’s early life Zionism was a mainly secular movement and the dominant force on the other side was a secular Arab nationalism. Since 1967, however, religion, nationalism and hunger for Palestinians’ land have fused to create a powerful constituency in Israel dedicated to retaining control of the whole of Jerusalem and Judaism’s holy places on the West Bank. Israel’s system of proportional voting has given the settlers and zealots a chokehold over politics. Among Arabs secular nationalism is meanwhile waning in the face of a powerful Islamic revival through the region. And a central dogma of the Islamists is that Israel is an implant that must be violently resisted and eventually destroyed.

One far-seeing Zionist, Vladimir Jabotinsky, predicted in the 1930s not only that the Arabs would oppose the swamping of Palestine with Jewish immigrants but also that “if we were Arabs, we would not accept it either”. In order to survive, the Jews would have to build an “iron wall” of military power until the Arabs accepted their state’s permanence. And this came to pass. Only after several costly wars did Egypt and later the PLO conclude that, since Israel could not be vanquished, they had better cut a deal. In Beirut in 2002 all the Arab states followed suit, offering Israel normal relations in return for its withdrawal from all the occupied territories, an opening which Israel was foolish to neglect.

The depressing thing about the rise of Hamas and the decline of the Fatah wing of the PLO is that it reverses this decades-long trend. Hamas’s victory in the Palestinian elections of 2006 had many causes, including a reputation for honesty. Its victory did not prove that Palestinians had been bewitched by Islamist militancy or come to believe again in liberating all of Palestine by force. But if you take seriously what Hamas says in its charter, Hamas itself does believe this. So does Hizbullah, Lebanon’s “Party of God”; and so does a rising and soon perhaps nuclear-armed Iran. Some analysts take heart from Hamas’s offer of a 30-year truce if Israel returns to its 1967 borders. But it has never offered permanent recognition.

There is worse. On top of the return to rejection and the growing role of religion, a third new obstacle to peace is the apparent crumbling of Jabotinsky’s iron wall.

In Lebanon three years ago, and today in Gaza, Hizbullah and Hamas seem to have invented a new military doctrine. Israel has deterred its enemies mainly by relying on a mighty conventional army to react with much greater force to any provocation. But non-state actors are harder to deter. Hizbullah and Hamas, armed by Iran with some modern weapons, can burrow inside the towns and villages of their own people while lobbing rockets at Israel’s. A state that yearns for a semblance of normality between its wars cannot let such attacks become routine. That is why today, as in the 1950s, Israel responds to pinpricks with punitive raids, each of which had the potential to flare into war. Israel’s operation in Gaza is designed not only to stop Hamas’s rockets but to shore up a doctrine on which Israel thinks its safety must still be based.

At Camp David in 2000 Israel and the Palestinians discovered that even with goodwill it is hard to agree terms. How to share Jerusalem? What to offer the refugees who will never go home? How can Israel trust that the land it vacates is not used, as Gaza has been, as a bridgehead for further struggle? But—and this is the fourth thing that keeps the battle alive—the two sides are seldom left alone to tackle these core issues.

For too long the conflict in Palestine was a hostage to the cold war. America was once neutral: it was Eisenhower who forced Israel out of Gaza (and Britain out of Egypt) after Suez. But America later recruited Israel as an ally, and this suited the Israelis just fine. It gave them the support of a superpower whilst relieving them of a duty to resolve the quarrel with the Palestinians, even though their own long-term well-being must surely depend on solving that conflict.

It may be no coincidence that some of the most promising peacemaking between Israel and the Palestinians took place soon after the cold war ended. But now a new sort of geopolitical confrontation stalks the region, one that sets America against Iran, and the Islamist movements Iran supports against the Arab regimes in America’s camp. With Hamas inside Iran’s tent and Fatah in America’s, the Palestinians are now facing a paralysing schism.

And so to Gaza

Tzipi Livni, Israel’s foreign minister, has been saying all week that, although Israel’s immediate aim is to stop the rocket fire and not to topple Hamas, there can be no peace, and no free Palestine, while Hamas remains in control. She is right that with Hamas in power in Gaza the Islamists can continue to wreck any agreement Israel negotiates with Mahmoud Abbas, the president of the Fatah-dominated Palestinian Authority on the West Bank. Mr Abbas, along with Egypt’s President Hosni Mubarak, may quietly relish Hamas being taken down a peg. Egypt is furious at Hamas’s recent refusal to renew talks with Fatah about restoring a Palestinian unity government.

There is a limit, however. Taking Hamas down a peg is one thing. But even in the event of Israel “winning” in Gaza, a hundred years of war suggest that the Palestinians cannot be silenced by brute force. Hamas will survive, and with it that strain in Arab thinking which says that a Jewish state does not belong in the Middle East. To counter that view, Israel must show not only that it is too strong to be swept away but also that it is willing to give up the land—the West Bank, not just Gaza—where the promised Palestinian state must stand. Unless it starts doing that convincingly, at a minimum by freezing new settlement, it is Palestine’s zealots who will flourish and its peacemakers who will fall back into silence. All of Israel’s friends, including Barack Obama, should be telling it this.