The cover of Not in God’s Name. Photo: provided.

An ominous shadow has swept across the Middle East and North Africa, leaving chaos and carnage in its wake. Mad men armed with Kalashnikovs and depraved convictions commit unspeakable acts – all safe in the knowledge that they are doing God’s work.

How the civilized world counters the Islamic State and its associates is the subject of Lord Jonathan Sacks’ timely new book, Not In God’s Name.

The former Chief Rabbi of Britain sees the battle against ISIS and similar groups as the defining conflict of the 21st century.

The frontline might be Syria and Iraq, but the battle is being fought everywhere and targets everyone — especially Jews.

In Europe, radical Islamists have spilled Jewish blood in Paris, Brussels, and Copenhagen in recent months. For Lord Sacks, Jews are the canaries in the cage. “The hate begins with Jews but never ends with them,” he says. “That’s why Jews must never be left to fight anti-Semitism alone. If it’s not safe to be a Jew in Europe today, it’s not safe to be a European in Europe today. Anti-Semitism is a sign of something larger and even more dangerous.”

He adds: “There’s significant antisemitism across the continent in France, Scandinavia, Holland, Belgium, Hungary, Spain and elsewhere. The threat level is not the same in Britain. We could not have asked for more loyal friends than our recent prime ministers, who have stood unequivocally with the Jewish community. But the dangers remain clear to us all.”

Lord Sacks rejects claims that anger at Israel is the root cause of this current antisemitism. “The problem is steeped in theological roots — an ancient sibling rivalry between Judaism, Christianity and Islam. For 1,000 years, Jews were the most conspicuous non-Christian minority in Christian Europe. Today, Israel is the most conspicuous non-Muslim presence in an otherwise Muslim Middle East. Jews have long been a conspicuous minority. Old prejudices must be acknowledged and overcome. We need to sit down in a respectful way and work out a peaceful future for all the people and faiths in the region.”

“Israel is not a key factor in what’s happening in Syria, Iraq, Afghanistan, Yemen or Libya. There’s an internal struggle within Islam between extremists and moderates — a dramatic split between those who are religious and respect democracy and engage with the world around them, and those who want to impose their beliefs on others by force. These are two completely different strains of religiosity. It is essential we engage with young Muslims to make sure they are fully integrated into British society. They need to hear strong religious voices, ones that are not radical or rejectionist.”

Sacks adds: “The late British Muslim leader, Doctor Zaki Badawi, who was head of the Muslim College in London and a friend of mine, was a wonderful moderate Islamic leader. There are many young moderate Muslims who are just as forthright and courageous as Zaki, but none has yet achieved his status. When that happens it will make a crucial difference in this struggle.”

According to Lord Sacks, extremist propaganda fills the vacuum left by an absence of moderate voices, particularly in Palestinian schools — where state-sanctioned indoctrination of children turns Jews into objects of disgust. Under the Palestinian education system, children are groomed for holy war and martyring themselves in terrorist attacks, rather than preparing for adulthood.

Lord Sacks says: “Palestinian schools and media tell children [that] non-believers are destined for hell. This has been the case for too long. The world must wake up and realize that if children are taught to hate, then all the military intervention in the world will not stop the spread of extremism. As a Jew, I wrestle with these issues every day. I hope Muslim leaders are doing the same.”

He speaks animatedly about Israel. “It is the only sound democracy in the region; a world technology leader full of creativity, idealism and exceptional energy. During my regular visits I meet young Israelis who fill me with inspiration. Why the world can’t accept Israel’s achievements and contribution is deeply troubling to me. Those who can’t see the obvious good in Israel harm themselves, not just Israel.”

When Lord Sacks finally stepped down as Britain’s Chief Rabbi in 2013, Prince Charles hailed him as a “light unto this nation.” How does he reflect on his 22 hectic years in the role?

“As chief rabbi, I was captain of a team, so there were naturally things I simply couldn’t say. Today, I can speak more freely and openly as an individual. I count those years in the Chief Rabbinate as an enormous privilege. And I am so impressed by the way my successor Chief Rabbi [Ephraim] Mirvis has taken over the mantle and continued to lead Anglo-Jewry with great warmth and skill. These days, I see my role as a teacher and, hopefully, someone who can inspire young people of all religions to engage in leadership to build a better future.”

Not In God’s Name by Jonathan Sacks is on sale now in hardcover, priced $28.95.