The Islamic State of Iraq and the Levant (ISIL) has changed its name more often than a rock band. The Sunni extremist group that has fought in Syria and plotted attacks in Saudi Arabia and Lebanon has now upped the stakes, advancing through Iraq and declaring itself the Islamic State (IS). In Iraq and Syria, the group has slaughtered Shiites and members of other religious groups it deems apostates, as well as Sunnis perceived as collaborators with the government. Its brutality has led to confusion about its aims and dangers. In the spirit of "know your enemy," let's dispense with some myths about IS.

1. The Islamic State is part of Al-Qaida.

IS and Al-Qaida have a long and tangled relationship: once close allies, now bitter enemies.

The Islamic State's many name changes over the years suggest this tension. Jihadist groups took off in Iraq after the 2003 U.S. invasion, and many coalesced around Abu Musab al-Zarqawi, a Jordanian who had worked with but was not part of Al-Qaida. Zarqawi eventually swore loyalty to Osama bin Laden in October 2004, and his group took the name Al-Qaida in Iraq. Yet even in its early days, the group bickered with Al-Qaida leaders over strategy, with Ayman al-Zawahiri and bin Laden stressing U.S. targets while al-Zarqawi and his successors emphasized sectarian war. They pursued conflict with Iraq's Shiites and tried to terrorize, not win over, Sunni Muslims.

Al-Qaida and IS differ on tactics, strategy and leadership. IS leader Abu Bakr al-Baghdadi embraces beheadings and crucifixions, and he focuses on local regimes and rivals, ignoring al-Zawahiri's credo of hitting the "far enemy" — the United States.

These differences came to a head in Syria, when al-Zawahiri designated the relatively more restrained Jabhat al-Nusra (JN) as Al-Qaida's local affiliate. Al-Baghdadi believes that his group should be in charge of jihadist operations in Iraq, Syria, Lebanon and Jordan. The two groups turned on each other, with their infighting reportedly killing thousands.

The dramatic campaign in Iraq may help Baghdadi eclipse al-Zawahiri. Al-Qaida is hounded by drones, while al-Baghdadi can claim that he is leading the fight against the apostates — a popular cause given the sectarianism sweeping the region.

2. The creation of the IS means the group is ready to govern.

IS now controls parts of eastern Syria and western Iraq. Much of this is desert, but IS also administers important cities such as Raqqah in Syria and Mosul in Iraq. As the Islamic State, it hopes to gain legitimacy by governing according to its extreme interpretation of Islamic law and thus gain more volunteers and financial support.

Islamist terrorists can govern successfully: Hamas has controlled Gaza for seven years now, and Hezbollah has exercised de facto control over parts of Lebanon for decades. Both groups run schools, hospitals and basic services. However, when IS's predecessors controlled western Iraq a decade ago, they ruled disastrously. Their brutality and incompetence alienated local Sunnis, contributing to the Awakening movement that almost obliterated the jihadists.

IS may appeal to Sunnis fearing discrimination from the Shiite-dominated government in Baghdad. However, most of those who can flee IS do so, including middle-class business owners and technicians who help run essential social services. In the end, IS may loot, sell oil on the black market and establish rudimentary services to prevent mass starvation — but don't confuse that for an efficient state.

3. The Assad regime in Syria is the Islamic State's bitter enemy.

Syrian President Bashar Assad's government declares itself to be at war with terrorists, while IS portrays itself as the defender of Sunni Muslims in Syria against "apostate" regimes such as Assad's. But both oppose Syria's moderate opposition, and by weakening the moderates, Assad undermines the greatest long-term threat to his rule.

The Assad government has at times refrained from military operations in some IS-controlled areas, used its air force to bomb moderate opposition forces fighting IS and bought oil from IS. If there were no IS, Assad would have to create it — and he sort of did. When unrest began in Syria three years ago, the struggle was widely portrayed as a mass revolt of citizens fed up with brutality and injustice. Assad depicted it as a sectarian fight against terrorists, and over time his rhetoric and tactics created a backlash among Sunni Muslims that transformed the conflict, with groups like IS rising. The Syrian people are increasingly left with the miserable choice of the Assad regime or radical Islamists.

With the Islamic State's advances in Iraq, this tactical alliance may be ending. Assad may reason that IS has become too powerful. In any event, the Iraqi government is Assad's ally, and losing control of border-crossing points to IS prevents the flow of supplies and fighters to the Syrian regime via Iraq.

4. IS is a formidable fighting force.

IS's stunning successes in Iraq — conquering Mosul and advancing on Baghdad — suggest a strong military organization. In fact, IS has perhaps only 10,000 fighters, and its attacks on cities such as Mosul involved fewer than 1,000 of them.

IS's military victories really reflect the weakness of the Iraqi army and the disastrous policies of Prime Minister Nouri al-Maliki. The United States has provided billions of dollars worth of military equipment to the Iraqi army, which on paper far outnumbers and outguns IS. The catch is that the Iraqi army will not fight. Al-Maliki appointed political loyalists, not competent leaders, as its senior officers. The regime's discrimination against Iraq's Sunnis has undermined morale among Sunni soldiers, who don't want to fight for a government they despise.

The recent recruitment of Shiite militias should halt IS advances in many areas. If the government can become more inclusive and win over moderate Sunnis, and if the Iraqi army can get its act together, IS's gains can be reversed. Those are big ifs.

5. The IS wants to attack the United States.

When released from prison in Iraq in 2009, al-Baghdadi told his U.S. captors, "I'll see you in New York" — a statement that now seems chilling. And on May 25, Moner Mohammad Abu-Salha, an American citizen who called himself Abu Huraira al-Amriki, carried out a suicide attack in Syria. IS's ranks include several thousand Europeans, whose passports offer them easy access to the United States, and perhaps one of the 100 or so Americans who have gone to Syria might conduct an attack upon returning.

IS certainly has the potential to be a threat to the homeland, and intelligence and law enforcement services must remain on alert. Yet for now it does not appear focused on the United States and is not prioritizing the struggle against the West — this is part of why it split with Al-Qaida. Al-Baghdadi's statement on New York may have been misreported, or possibly a joke, as many of his guards were New Yorkers. More important, IS's actions so far suggest that it wants to use Western recruits as fodder for its local and regional wars. Creating and sustaining an Islamic state and fighting apostates are the priorities.

IS does pose a threat to Iraq and to regional stability. But the Obama administration should beware of swallowing the group's propaganda or assuming that it will inevitably become stronger.

Daniel Byman is a professor in the security studies program at Georgetown University and the research director of the Saban Center for Middle East Policy at the Brookings Institution. He wrote this article for the Washington Post.