National conflicts are basically rational. They concern territory. They can usually be solved by compromise.

Religious conflicts are irrational. Each side believes in an absolute truth, and automatically considers everybody else as infidels, enemies of the only true God.

There can be no compromise between True Believers, who believe that they are fighting for God and get their orders straight from Heaven. "God Wills It" shouted the Crusaders and butchered Muslims and Jews. "Allah is the Greatest" shout fanatical Muslims and behead their enemies. "Who is like you among the Gods!" cried the Maccabees, and annihilated all fellow Jews who had adopted Greek manners.

THE ZIONIST movement was created by secularized Jews, after the victory of the European Enlightenment. Almost all the founders were convinced atheists. They were mostly quite ready to use religious symbols for decoration, but were roundly denounced by all the great religious sages of their time.

Indeed, before the creation of the State of Israel, the Zionist enterprise was remarkably free of religious dogmas. Even today, extreme Zionists talk about the "Nation State of the Jewish People", not of the "Religious State of the Jewish Faith". Even for the "national religious" camp, the forerunners of today's settlers and semi-fascists, religion was subordinate to the national goal – the creation of a national Jewish state in all the land between the Mediterranean Sea and the Jordan River.

This national onslaught met, of course, with the resolute resistance of the Arab national movement. After some initial hesitation, Arab national leaders turned against it. This resistance had very little to do with religion. True, for some time the Palestinian resistance was led by the Grand Mufti of Jerusalem, Haj Amin al-Husseini - not because of his religious standing but because he was the leader of Jerusalem's most aristocratic clan.

The Arab national movement was always decidedly secular. Some of its most outstanding leaders were Christians. The pan-Arab Baath ("Resurrection") party, which came to dominate both Syria and Iraq, was founded by Christians.

The great hero of the Arab masses at that time, Gamal Abd-al-Nasser, though formally Muslim, was quite un-religious. Yasser Arafat, the leader of the PLO, was a pious Muslim in private, but under his leadership the PLO remained a secular body with many Christian ingredients. He spoke about liberating East Jerusalem's "mosques and churches". For some time the official aim of the PLO was to create in Palestine a "democratic and non-denominational" state.

SO WHAT has happened? How did a nationalist movement turn into a violent, fanatical religious one?

Karen Armstrong, the nun-turned-historian, pointed out that the same thing happened practically simultaneously in all three monotheistic religions. In the US, evangelical Christians now play a large role in politics, in close cooperation with the Jewish right-wing establishment. All over the Muslim world, fundamentalist movements are gaining strength. And in Israel, a messianic Jewish fundamentalism is now playing a larger and larger role.

When the same thing happens in such diverse countries and religions, there must be a common cause. What is it?

It is easy to speak about something nebulous with the German title of Zeitgeist, the spirit of the times, but that really explains very little.

In the Muslim world, the bankruptcy of liberal, secular nationalism has created a spiritual void, an economic breakdown and national humiliation. The shining promise of Nasserism ended in abject stagnation under Hosny Mubarak. The Baath dictators in Baghdad and Damascus failed in creating modern states. The militaries in Algeria and Turkey did not do much better. After the overthrow of the elected democratic Iranian leader, Mohammed Mossadeq by oil-grabbing Western powers, the luckless Shah could not fill the void.

And, all the time, there was the humiliating sight of Israel, which grew from a despised little foreign implant into a formidable military and economic power, and which easily trounces Arab states again and again.

After every new war, Muslim people ask themselves: What's wrong? If nationalism has failed both in peace and in war, if both capitalism and socialism did not succeed in creating a sound economy, if neither European humanism nor Soviet communism succeeded in filling the spiritual void, where is the solution?

The thunderous reply comes from the depths of the masses: "Islam is the Answer!"

LOGIC WOULD have it that the Israeli reply would be the opposite.

Israel is a success story. Not only does it have a mighty military machine and credible nuclear capabilities, but it is a technological power and has a comparatively sound economic basis.

But messianic fundamentalism, closely allied with an extreme nationalism, is now dictating our course.

On the eve of the recent war, the commander of the Giv'ati brigade published an order-of-the-day to his officers. It shocked many.

The Giv'ati brigade was an outstanding fighting force in the war of 1948 (I was one of its original fighters and wrote two books about it). We took great pride in its composition. The fighters were a mixture of the sons of the metropolitan Tel Aviv elite and the poorest surrounding slums – a mixture that was eminently successful and proved itself in battle.

The brigade commander was a former German communist underground fighter under the Nazis, who converted to Zionism and became a member of a very left-wing kibbutz. So were most of his staff officers. I don't remember a single soldier in the brigade who wore a kippah.

Imagine our shock when the current brigade commander called for a holy fight to fulfill God's will. Colonel Ofer Winter, who in his youth attended a religious-military school, had this to say to his soldiers on the eve of battle:

"History has chosen us as the spearhead of the fight against the Gazan terrorist enemy, who abuses and curses the God of Israel's battles…I raise my eyes to heaven and call with you: 'Hear oh Israel, the Lord our God, the Lord is One'. Oh Lord, the God of Israel, make us succeed on our way, as we are going to fight for Israel against an enemy who curses your name!"

The official aim of the Israeli army in this campaign was to guard the border and stop the launching of rockets at Israeli towns and villages. But that is not the aim of the Colonel. He sent his soldiers to die (three of them did) for the God of Israel, against those who curse his name.

If this officer were the only religious fanatic in the army, it would be bad enough. But the army is now full of kippah-wearing officers who have been indoctrinated with religious fervor and indoctrinate their soldiers in turn with the same spirit.

The Zionist-religious party and its fanatical rabbis, many of them outspoken fascists, have been working for years to systematically infiltrate the army's officer corps. It’s a process of natural selection: officers who are loath to act as colonial masters in occupied territories leave the army to become high-tech entrepreneurs, while messianic fanatics are sent to fill their place.

The colonel, by the way, has not been reprimanded or harmed in any way. On the contrary, he has been lauded during the war as an exemplary battle commander.

ALL THIS leads me to ISIS – the Islamic State of Iraq and al-Sham (Greater Syria), which recently changed its name to just "Islamic State". The change means that the former states, created by the Western colonialists after World War I, are abolished. There is going to be one Islamic state that includes all former and present Islamic territories, including Palestine (including Israel).

This is a new and frightening phenomenon. There are, of course, many Islamist parties and organizations in the Muslim world – from the Turkish ruling party to the Egyptian Muslim Brotherhood to the Palestinian Hamas. But almost all of them restrict their fight to their national countries – Turkey, Syria, Palestine, Yemen. They want to attain power and rule their countries. Even Osama bin Laden wanted mostly to take over his Saudi homeland.

ISIS is something quite different. It wants to destroy all states, especially the Muslim states carved out by Western imperialists from Islamic land. With horrible savagery, elevated to a religious symbol, it sets out on its way to conquer the Muslim world, and then the globe.

It may seem a ridiculous aim, given that the whole enterprise consists of a few thousand fighters. But this tiny force has already conquered a huge part of Syria and Iraq. It expresses the Muslim longing for restoring ancient glory, their hatred of all those (including us) who have humiliated Islam, a thirst for spiritual values. One cannot help being reminded of the beginnings of the Nazi movement – its resentments, its thirst for revenge, its attraction for all the poor and humiliated.

It may take only a few years to become a huge force, threatening all the states of this region.

DOES IT threaten Israel? Of course it does. If its dynamism holds, it will overthrow the Assad regime and reach the Israeli border, where other Islamic rebels have already shot the first few rounds this week.

With such a menace looming in the north, it seems ridiculous to fight against a miniscule Islamic-patriotic force in Gaza – even if curses the name of the Lord.

There may be very little time left to make peace with the Arab national movement, and especially with the Palestinian people – including both the PLO and Hamas – and join the fight against the Islamic state.

The alternative is frightening.