AT least the early Muslim conquerors in the 8th and 9th centuries were moderately humane: if Christians, Jews and other unbelievers in the countries they overran were prepared to pay the Islamic tax on infidels (known as the dhimmi), the Muslim conquerors would refrain from beheading them, crucifying them or putting them to the sword.

Of course, the unbelievers were treated as third-class citizens but, arguably, this was better than execution.

The Islamic State of Iraq and the Levant (Isis), whose barbaric forces now occupy much of Iraq and Syria, are not so kind.

Christians, Alawites, Kurds and Druze have fled for their lives. Isis is an organisation so barbaric that it has even been condemned by al Qaida.

Once again western leaders and governments have backed the wrong horse — in fact, they have backed a whole string of wrong horses. Their folly was evident 35 years ago when the US and the UK actually armed the Taliban in Afghanistan against the Russians. Meanwhile, a relative peace prevailed across North Africa and the Middle East under the control of pro-western dictators.

Then came the two Gulf Wars followed by the Arab Spring and the West backed the Muslim insurgents against the dictators.

The dewy-eyed sentimentality of the western powers led them foolishly to imagine that the uprisings would result in the spread of “democracy” in the Muslim world.

A long time ago, speaking of the brutal Nicaraguan dictator Somoza, President Harry Truman is reported to have said: “He may be a bastard, but he’s our bastard.”

The same might be said of Sadat, Mubarak, Assad (father and son) and even of Saddam Hussein and other regional despots. They were, and are, mightily unpleasant — but now we’re witnessing the alternative and it’s incomparably worse.

By deposing the dictators, the West did the Muslim insurgents’ work for them. With profound stupidity, the West was seriously contemplating arming the Sunni uprising in Syria against Assad just last year. Many of these insurgents are now enthusiastic members of Isis, psychopaths who are currently carrying out wholesale executions in the parts of Iraq and Syria they have occupied.

Their aim is the creation of a fundamentalist Islamic regime based on Sharia across North Africa and the Middle East.

They have proclaimed this aim frequently.

Why should we not believe them?

The insurgents may be barbaric but they are not stupid. They have seen the western powers withdraw from Afghanistan and Iraq and they conclude, rightly, that the West is unwilling to employ arms as would be necessary to thwart their ambitions.

And that’s not all. The insurgencies have created havens for terrorists, training camps for the several hundred radicalised young British Muslims who are now fighting there with the militant Sunnis, al Qaida and now Isis. We are reliably informed by our intelligence services that many of these fanatics intend to return to Britain and perpetrate acts of terror here.

It’s really not very bright of our leaders to have encouraged the setting up of a terrorist training camp on Europe’s doorstep.

It’s suicidal of them to lack the will to do anything about it.