In Raqqa, Syria, the Islamic State's "caliphate" has already become a reality. All women in the city are required to wear the niqab veil and pants are banned. Thieves have their hands hacked off and opponents are publicly crucified or beheaded, with the images of these horrific acts then posted on social networks.
The few hair salons that are still open are required to black out the pictures of women on the packaging for hair dye solutions. Weddings are only permitted to take place without music. And at livestock markets, the hindquarters of goats and sheep must be covered in order to prevent men from viewing their genitalia and having uncomely thoughts.
Any person caught out on the street during the five daily prayer times is risking his or her life.
The jihadists with the Islamic State, or IS, are acting out their fantasies of omnipotence in the name of God. They're murdering, torturing and forcing families to give their daughters away for marriage to Islamist fighters coming in from abroad. One girl whose family agreed to marry her off took her own life.
In Syria, IS militants and their predecessors have killed countless people in recent years, and over 160,000 in total have died during the Syrian civil war. Yet it is only now that the world is waking up, now that the conflict has spilled into Iraq, where the Islamic State also appears to be spreading its tentacles without much resistance.
Pictures were needed in order for the international community to understand the scale of the horror unfolding in Iraq and just how inhumanely the Islamic State terrorist militia is acting. Images allowed the global community to become witnesses to the plight of the Yazidis, followers of one of the world's most obscure religions, as they were forced to flee into the mountains, begging for help as they died of thirst. In the eyes of the IS fanatics, the Yazidis are "devil worshippers," people who deserve to die.
It was only this threat of genocide that moved the global community to act. Countries around the world quickly united in the battle against IS, by far the world's most brutal, most successful -- and most sinister -- jihadist troop.
In recent weeks, IS fighters managed to drive out the peshmerga fighters of the Kurdish Autonomous Government of Iraq with disturbing ease. In some cases the Kurdish soldiers, previously considered the best Iraq has to offer, didn't even resist. The IS threat has even brought rapprochement between the peshmerga and the Kurdistan Worker's Party (PKK), who had long been enemies.
A Common Enemy for the US and Iran
Further afield, the United States and Iran have likewise found a common enemy in the Islamic State. And within just a few weeks time, countries in the West have proven capable decisions that would have been inconceivable not long ago. European countries, for example, now want to deliver weapons to the Kurds, seeing them as the only reliable allies in the region. Meanwhile, the US, which withdrew its troops from Iraq just two years ago, saw no alternative to intervening in the new conflict with special forces and fighter jets.
Little could do more to underscore the failure of America's Iraq adventure than the bombing of US weapons systems by US fighter planes in northern Iraq in recent weeks. They also had to eliminate armored vehicles and mobile artillery units that they had once delivered to the Iraqi army -- and which fell into the hands of the Islamic State in June.
But the IS isn't just brutal, it is also sophisticated. Until the peshmerga regained the territory late last week, IS even temporarily had control of the Mosul dam, the largest rivers and, with them, large parts of Iraq's supplies of drinking water. And it still controls large stocks of wheat and important agricultural areas.
The Greatest Terrorist Threat Since al-Qaida
And so it is that the caliphate of the Islamic State suddenly appeared on the maps, a nightmarish realm that stretches from northeastern Syria deep into Iraq, led by a self-appointed caliph named Abu Baqr al-Baghdadi.
How could it have come to this?
In the past few years, the greatest terrorist threat since al-Qaida has slowly emerged. But the development was not unavoidable. There are two significant contributing factors that have allowed large parts of Iraq and Syria to descend into jihadist territory. One is the civil war in Syria, which enabled fighters from Iraq and the rest of the world to gain experience in war, it helped them find donors and it gave them a cause to fight for. The international community's delayed reaction in responding to the Syrian conflict also played a role.
But the origins of IS go back to the Iraqi civil war in the period that followed the US invasion in 2003. There's no way the organization could have grown as fast as it did without support from Iraqi Sunnis. For years, they were shunted aside by the government of Shiite Prime Minister Nouri al-Maliki, and many are still caught up in the nostalgic resentment of having lost the earlier supremacy in society they enjoyed during the era of Saddam Hussein, himself a Sunni.
After resisting the move bitterly, Maliki finally resigned from office last week. His designated successor, Haidar al-Abadi, is also a Shiite. Leaders of the country's Sunni tribes declared last week they would be willing to negotiate with him. Indeed, an understanding between the Shiites and Sunnis would be decisive in any effort to drive back the Islamic State. Still, that alone will not be enough.
"Unfortunately, the IS has been allowed to grow and develop to such an extent that any strategy to really counter it will have to take years and very significant resources," says Charles Lister of the Brookings Institution, who researches the group intensively in the Doha, Qatar office of the Washington-based think tank. He argues that military measures won't suffice for the task.
IS has an estimated 6,000 to 8,000 fighters in Syria and, with allied militias, more than 15,000 in Iraq, though such figures are imprecise. Those fighters include some 2,000 to 3,000 fighters believed to be of European origin.
When it conquered Mosul, IS gained access to almost a half-billion dollars in cash, making them independent of donations from Gulf states and Saudi Arabia. Furthermore, the organization sells oil and gas from fields it has conquered, it controls water and electricity and it collects taxes.
IS even offers social security benefits to residents of areas under its control -- just like a real country, says Brookings' Lister. Whatever regions the IS captures, it simply continues paying local workers -- people like the employees at the Mosul dam or even those working in restaurants.
A Fanaticized World
But how are things looking inside the Islamic State? For three weeks, the journalist Medyan Dairieh was allowed to stay in Raqqa, the capital city of the caliphate. IS fighters themselves determined what he was allowed to see and what he was allowed to film. The result is a 45-minute film that sometimes seems like propaganda but which nevertheless provides the first real view of life inside the caliphate. It shows a world of fanatical people in which adolescents shout into the camera, declaring war on infidels.
The Islamic State even has a spokesman in Raqqa -- Abu Musa, a young man with a beard who has a penchant for wearing Ray Ban sunglasses. He uses his position to send a message to America, saying things like: "Don't be cowards who attack us with drones. Send your soldiers instead, the ones we already humiliated in Iraq."
Also visible in the video is a patrol of the Hisbah, the Islamic State's morals police. "Just try to find a person who is selling alcohol," boasts the head of the patrol. While driving by, he warns the husband of a fully veiled woman that she shouldn't lift her gown at all while walking.
The history of the organization that would later become IS began before the US invasion in Iraq. In the subsequent years, a Jordanian calling himself Abu Musab al-Zarqawi, began conducting a series of spectacular bombing attacks against Shiites in his effort to provoke a religious war.
Zarqawi officially closed ranks with al-Qaida. Before he was killed, al-Qaida leader Osama bin Laden even criticized the brutality of the terrorist group's Iraqi offshoot in a document that would emerge later. Even back then, Zarqawi's men unsettled their Sunni allies with absurd rules. These included, for example, bans on ice cream, which didn't even exist during the Prophet Muhammad's life, or the sale of cucumbers at markets because they could encourage prurient thoughts.
Before he was killed in a US air strike in 2006, Zarqawi fomented a civil war that still threatens to tear Iraq apart today. After his death, the organization renamed itself as the Islamic State in Iraq and lost much of its punch after the Americans began to form coalitions with Sunni tribes.
The Region's Strongest Militia
It was Abu Bakr al-Baghdadi, the leader of the organization since 2010, who transformed IS into what it is today. IS expert Lister says he has introduced a more professional and methodical military approach, adding that Baghdadi adopted much of Zarqawi's approach but doubled its effectiveness. He also says that Baghdadi possesses a higher level of authority because, in contrast to men like bin Laden, he also has a religious education, with a PhD in Islamic Theology.
Still, he apparently doesn't control his military himself, instead relying on a leadership circle comprised largely of former officers and ex-officials from Saddam Hussein's Baath Party. They are kept sealed off from day to day IS operations with fighters in the field only know their local "emir," who in turn only has ties to his provincial emir.
Observers today consider IS to be the region's strongest militia. But it took years for it to secure that position, a process that led from the beginnings of the Iraq war through the civil war in Syria almost a decade later.
Growing Support Abroad?
After the insurgency against Bashar Assad began in Syria in March 2011, the regime released many jihadists from high-security prisons who had previously fought in Iraq, a move meant to support Assad's claim that he was fighting against radical Islamists.
At the time, though, the opposition fight was largely being waged by the Free Syrian Army (FSA), a conglomeration of army deserters and civilians. The FSA may not have been Islamic, but there was also little to it beyond a name. There were few overarching command structures and FSA never had the money or weapons needed to defeat Assad. The West was concerned that weapons might fall into the wrong hands if it supported FSA.
Today, it's not just in the United States that a debate is flaring over whether the West could have stopped IS if it had provided more concerted support to strengthen the moderate opposition at the right time.
Former US Secretary of State Hillary Clinton, who could become the Democratic Party's next presidential candidate, has been openly critical of Obama. His refusal to provide support to the opposition in Syria early on "left a big vacuum" that fostered the rise of IS, she argues.
So who's right? It's hard to say. Brookings expert Lister believes IS still would have been able to gain a foothold in Iraq, but that it would nevertheless have made sense to support the moderate rebels in Syria in the beginning in order to keep the IS at bay.
At some point in the summer of 2011, eight men crossed the border from Iraq into Syria. One was Abu Mohammad al-Golani. IS chief Baghdadi had dispatched him on a mission to establish another branch of al-Qaida in Syria, the Nusra Front, marking the start of the jihadist segment of the Syrian civil war.
Al-Golani wanted a departure from the extreme methods deployed by al-Qaida in Iraq and eschewed meting out brutal punishments. Nusra established itself quickly as the most effective forces in Syria and even became popular among the people. Its fighters delivered yeast to bakeries and distributed food provisions.
A Split Among Jihadists
But in April 2013, Baghdadi sought to win back control of his Syrian creation. He declared himself the leader of al-Qaida in Iraq and Syria, which from that point on would carry the name Islamic State of Iraq and Syria (ISIS). But Nusra leader al-Golani rejected the demand and secured the support of the global head of al-Qaida, Ayman al-Zawahiri. That marked that moment at which Baghdadi parted ways with al-Zawahiri and al-Qaida. Al-Nusra also split. Some of the fighters remained loyal to al-Golani and al-Qaida, while others, including most foreign fighters, defected to Baghdadi. Even back then, Baghdadi viewed himself as the head of a state and not just one militia leader among many. He even appointed himself the leader of all faithful.
In May 2013, ISIS conquered the city of Raqqa in Syria from Nusra and later turned it into its capital. Since then, the jihadists have been fanning out across northern Syria, nourished by a constant stream of new radicals from Tunisia, Saudi Arabia, Egypt, Europe and even Indonesia.
The Islamists did little to combat the regime, instead picking fights with other rebel groups. So it came as little surprise when, in January, an alliance of opposition from almost every group drove the jihadists out of northwestern Syria within a matter of just weeks. It didn't last long. After regrouping, the IS returned and began a new offensive with weapons secured in Iraq.
In recent weeks, the jihadists focused mainly on seizing areas in northern Syria. IS fighters took control of several places west of the Euphrates River near the Turkish border. In doing so, they cut off rival fighters with the Free Syrian Army from important supply lines. The fighters were already under pressure in Aleppo, where they are facing off against troops loyal to Assad's regime. It's unlikely they'll be able to hold out for much longer.
IS Struggles to Gain Traction in Syria
Contrary to IS propaganda, it is in no way true that all Sunnis in Syria are welcoming the jihadists as liberators. There has, for example, been resistance to the new rulers in the Deir el-Zour province. The powerful Shaitat clan has also revolted against IS in several places.
There are even small signs of resistance in the IS stronghold of Raqqa. In mid-July, fundamentalists there condemned two women to death by stoning for alleged infidelity. Witnesses said that most of the residents ordered to assemble in Bajaa Park refused to take part in the stoning. The jihadists had to step in to do the job themselves.
Although IS has succeeded in attracting large numbers of Islamists in Iraq to its cause, it has failed to do so in Syria. Propaganda videos aimed at Syria mostly include men with North African or Saudi Arabian accents. They are at the top of the IS hierarchy and they are also the ones introducing Sharia courts in Syria.
That's one of the reasons social networks are so important for the Islamic State's propaganda efforts. IS supporters relish their reputation for brutality, tweeting photos of crucifixions and massacres. The group even publishes its own magazine in PDF format, with the aim of attracting additional fighters from around the world to the caliphate.
Support among European Radicals
And, with support apparently growing in Europe, it seems to be working. In recent weeks, Islamic State flags could be seen at protests in Paris and Brussels and last week, a flag was spotted flying outside a home in New Jersey. Meanwhile, on busy Oxford Street in London, Islamists were handing out leaflets about the Islamic State, rejoicing that the caliphate is here and calling for people to migrate to the "Khilafah," the spelling used by IS for the caliphate. Some fanatics seem to regard the IS fighters with pop star-like status.
It's not just men who are rushing off to join the caliphate. Fanatic women seeking jihadist husbands are also making their way. The person behind the "Umm Layth" blog presents herself as a British immigrant to the caliphate. On it, she posts photos of herself and her "sisters" -- covered in black, of course -- and calls on readers to follow in her footsteps to the Islamic State, asking: "How can you not want to produce offspring who may be, God willing, part of the great Islamic revival?"
She also offers fashion tips for women who have already been convinced to make the trip. "There are many materialistic things that can be found here," she writes. "However, it is better for you to bring clothes, shoes etc. from the West. There are clothes here, but ... the quality is really bad."
Arrests in Germany
It is believed that several hundred fighters have made their way from Germany to Syria. SPIEGEL has obtained information indicating that the Federal Prosecutor's Office is investigating more than two dozen cases of suspected members or supporters of the Islamic State, including a number of people who hold German citizenship. Prosecutors have likewise charged several for supporting a foreign terrorist organization.
It appears that IS is also dispatching experienced campaigners from the Middle East back to Germany in order to raise money, gather materials needed for the armed conflict and even to help launch jihad in Europe.
On Nov. 13, 2013, investigators detained three suspected Islamists at a rest stop along the autobahn near Stuttgart. They were carrying medication, camouflage clothing, night-vision devices and €6,250 ($8,329) in cash and they appeared to be making their way to Syria. At least one, a Lebanese man, had previously received training in a camp. One of his helpers was a German citizen.
At the end of May, the Federal Prosecutor's Office placed charges against the three men, and on June 6 it pressed charges against an additional man, a 20-year-old German. Investigators believe he also went through six months of weapons training in Syria. After he returned to Germany, police arrested him in Frankfurt. He is suspected of preparing a "serious act of violent subversion."
So far, the Islamic State has had no real interest in conducting any kind of spectacular attack in the West. But, as experts like Charles Lister note, that could be one of the next steps. After all, IS has essentially succeeded in doing everything al-Qaida has done with the noted exception of carrying out a foreign attack.
By Markus Feldenkirchen, Christoph Reuter, Mathieu von Rohr, Jörg Schindler, Samiha Shafy and Christoph Sydow