Barack Obama says he will this week lay out his "game plan" for dealing with the forces that claim to be an Islamic State. The choice of language is revealing. In fact, it reveals much of the problem.

Obama might think of it as a "game" but it is, for the enemy, a cause for which they are not only prepared to die but hope to die.

"You are scared of death, while we love death," said the first known American suicide bomber of the Syrian civil war, 22-year-old Mohammad Abu-Salha, of Florida, in his YouTube posting addressed to the US president.

But why?

We know why the forces of the civilised world come reluctantly to the fight, carefully hedging their commitments with promises that no ground troops will be sent in. Henry Kissinger, frustrated at Obama's slowness to take the lead, called on the weekend for him to launch an "all-out attack".

But why are thousands, perhaps tens of thousands, of IS fighters seeking death? Why are they coming from scores of countries around the world? Like Andre Poulin, thought to be 24, who described himself as a "regular Canadian", fond of hockey and camping before joining IS.

"Come and join before the doors close," he urges in his final video clip before the camera cuts away to the scene of his martyrdom, when he runs headlong into a hail of enemy bullets in the Syrian desert.

What doors? A powerful draw for many of the recruits is the belief that this is not just any ordinary war against the infidels but the fight foretold in prophecy to be the battle at the end of time.

Some predictions in Islamic eschatology say that the final battle will be fought in Sham, which is the name for Greater Syria, including Syria, Jordan, Lebanon Palestine and Israel.

"Indeed, within some extremist circles, the Syrian conflict is known as the 'one-way ticket jihad' because anyone goes there to fight will be able to stay and see Islam's final victory," explains Sidney Jones, an American expert on terrorism who bases herself in Jakarta at the Institute for Policy Analysis of Conflict.

Jones cites a hadith, a report of the words of the prophet, that jihadis frequently quote: "You Muslims will fight on the Arabian Peninsula and Allah will give you victory. You will fight the Persians and Allah will give you victory. You will fight the Romans and Allah will give you victory. Then you will fight Dajjal, and Allah will defeat him for you."

Meaning? Jihadist groups interpret the reference to the Arabian Peninsula to  mean the Arab Spring revolts against "apostate" Arab regimes, says Jones.

They interpret Persia as meaning the war against Shiite Muslims, including against the Assad government in Syria.

And the Romans? They are "represented today by the West, including America, Australia and Europe", Jones writes in a January report. Dajjal is the Muslim anti-Christ.

Where Westerners see a military project in need of a "game plan," the believers on the ground in Syria and Iraq tell themselves it is a grand contest, the ultimate struggle for redemption, to be crowned by glory. 

Of course, not all of the people going to fight with the jihadists see it in these terms. In one well-publicised instance, a pair of British citizens headed for Syria ordered copies of Islam for Dummies and The Koran for Dummies. Many are simply thrillseekers.

Some are social outcasts and failures, like Australia's Khaled Sharrouf, the man who congratulated his little boy for holding a severed head. He was facing jail ultimately in Australia, but in Iraq he has licence to commit murder and mayhem under the cover of religious warfare.

Yet the movement does preach its ideology, and many of its followers are prepared to embrace death for it. So when Julie Bishop says "we have to be wary of claiming to be able to eliminate ISIL, because you're talking about an ideology," she is correct.

You cannot defeat an ideology, and certainly not with a game plan. "Have we destroyed al-Qaeda?" she poses. Of course not. IS is actually an al-Qaeda offshoot. You can't defeat an ideology. You can only discredit it.

So crediting the movement is a poor way to begin discrediting it. The West generally has been astonishingly credulous in accepting the name of the movement on its own terms.

It earlier called itself Islamic State in Iraq and the Levant (ISIL) before declaring itself, more grandly, Islamic State. Governments around the world have unquestioningly accepted these names and the world media has followed suit.

The problem? This cedes two tremendous achievements to a gang of marauding thugs. First, it accepts their claim to be Islamic, when in fact they are an extremist perversion of that great religion. To call these butchers Islamic is to demean true Muslims everywhere.

Second, it grants their claim to be a state. The UN calls them not a state but terrorists. Obama still refers to them publicly as ISIL. Tony Abbott, correctly, refuses to use the lofty name it gives itself. He prefers to call the gang the "death cult." A research institute in Egypt proposes calling them Qaeda Separatists in Iraq and Syria, or QSIS.

It will be a major advance when Obama does ultimately reveal his strategy for rendering the terrorists harmless. But this is not a game, and they are not an Islamic State.

The world needs to deal with these base terrorists with the same determination they have shown in slaughtering all who refuse to submit. It's time to close the door on the barbarians.

Peter Hartcher is the international editor.

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