President Obama has authorized airstrikes in Iraq to halt the sweeping advance of militants known as the Islamic State. The group has captured large swaths of northern Iraq, including the country’s largest dam, near Mosul, and its largest Christian town. The militants have advanced to a half-hour drive from the Kurdish regional capital, Erbil, where the United States has a consulate and military personnel. The United States has also begun dropping relief supplies to Iraqis forced to flee their homes. About 40,000 members of the Yazidi religious minority remain trapped on Mount Sinjar near the border with Syria, surrounded by rebels and slowly dying of thirst. Obama said airstrikes may be needed to prevent what he called a “potential act of genocide.”

President Obama: “When we have a mandate to help — in this case, a request from the Iraqi government — and when we have the unique capabilities to help avert a massacre, then I believe the United States of America cannot turn a blind eye. We can act, carefully and responsibly, to prevent a potential act of genocide. That’s what we’re doing on that mountain.”

[Update: Just before 9 a.m. on Friday, the Pentagon announced U.S. aircraft have launched strikes against Islamic State artillery in Iraq.]

Fighting has resumed in Gaza after the expiration of a 72-hour ceasefire. Israel said it launched airstrikes after Palestinians resumed rocket fire. Palestinian officials say a 10-year-old boy was killed earlier today when an Israeli airstrike hit near a mosque in Gaza City. Six people were wounded. Hamas rejected an extension of the three-day ceasefire, saying that Israel had failed to meet a key Palestinian demand to ease the crippling blockade of Gaza. The month-long Israeli offensive has killed nearly 1,900 Palestinians, most of them civilians and more than 400 of them children. Israel says 64 of its soldiers have been killed, along with three civilians. We’ll have more on Gaza later in the broadcast.

An author and professor has reportedly lost his job after publicly criticizing the Israeli siege of Gaza. Steven Salaita is the author of “Israel’s Dead Soul” and a contributor to outlets including The Electronic Intifada. After posting a series of tweets critical of Israel, he was reportedly told he would no longer have a job at the University of Illinois at Urbana-Champaign. He was due to start work there in the American Indian Studies Program this month. The American Association of University Professors expressed concern, saying, “Whether one finds these views attractive or repulsive is irrelevant to the right of a faculty member to express them.” More than 10,000 people have signed a petition for his reinstatement.

The World Health Organization has declared a record outbreak of the deadly Ebola virus an international public health emergency. Liberia and Sierra Leone have deployed soldiers to blockade hard-hit areas, and Liberia’s foreign minister told the Thomson Reuters Foundation “the health care system is collapsing.” The tiny West African country of Benin has reported two possible Ebola cases, but nearly all infections have been in Liberia, Sierra Leone and Guinea, with several in Nigeria. In the United States, Thomas Frieden, head of the Centers for Disease Control and Prevention, said he has activated the agency’s highest level of response.

Thomas Frieden: “The current outbreak is a crisis. It is unprecedented. And it’s unprecedented in five different ways. First, it’s the largest outbreak ever. In fact, at the current trend, within another few weeks, there will have been more cases in this outbreak than in all previous recognized outbreaks of Ebola put together.”

Secretary of State John Kerry is in Afghanistan today for a second day of talks on the country’s disputed presidential election. Kerry is urging both candidates to accept an ongoing, internationally monitored audit so a candidate can be in place before an upcoming NATO meeting next month.

The Obama administration resumed talks with Iran Thursday over Iran’s disputed nuclear program. State Department spokesperson Marie Harf called the discussions “constructive” and said meetings on the issue would continue.

Newly leaked documents show a German spying company that provides technology to governments around the world helped Bahrain spy on its citizens during a crackdown on pro-democracy protests. Analyzing documents released by a hacker this week, the news site The Intercept reports that the company FinFisher helped Bahrain install spyware on dozens of computers, including those of human rights lawyers and an opposition leader who is now in prison.

President Obama has signed a bill to address the crisis in veterans’ healthcare. The bill will expand staffing and allow veterans facing lengthy commutes or wait times to seek private medical care.

In Michigan, a jury has reached a verdict in the killing of the unarmed African-American 19-year-old Renisha McBride. Theodore Wafer has been convicted of second-degree murder and manslaughter for shooting McBride on the porch of his Detroit-area home last November. McBride was apparently seeking help after a car crash when Wafer shot her in the face through his screen door. He claimed he had feared for his life. The killing sparked mass protests as prosecutors took about two weeks to file charges against Wafer. He now faces up to life in prison. Responding to the verdict, McBride’s mother, Monica McBride, said justice has been served.

Monica McBride: “I just — I wanted justice. You know, looking at him, to know that justice needs to be served. You did cold-blood murder. That was murder. That was no accident. That was not self-defense. He did murder.”

Hawaii is bracing for a rare double threat from a tropical storm and hurricane set to hit within days of each other. Thousands have already lost power from Tropical Storm Iselle, with Hurricane Julio expected this weekend or early next week. The last time a hurricane or tropical storm hit Hawaii was 22 years ago. Climate models have predicted Hawaii will see an increase in such storms as a result of global warming.

In Canada, First Nations leaders are calling for immediate action to clean up a massive spill at a copper and gold mine, saying it is one of British Columbia’s worst environmental disasters. The rupture of a tailings pond at Imperial Metals’ Mount Polley mine spilled more than a billion gallons of silt laden with metals into area waterways.

Argentina has taken steps to sue the United States at the International Court of Justice over a debt dispute that sent the country into default. In a petition to the U.N. tribunal, Argentina accuses U.S. courts of violating its sovereignty by siding with vulture funds led by billionaire Paul Singer. The hedge funds have demanded full repayment after buying Argentina’s debt for bargain prices after its financial crisis. The lawsuit will only take hold if the United States accepts the U.N. court’s jurisdiction. Argentine President Cristina Fernández de Kirchner announced the suit Thursday.

President Cristina Fernández de Kirchner: “Today a demand was brought before The Hague, which is the international court of the United Nations, against the United States of America for the activity of its judicial power. This is not an action against the country. It simply means that dependent powers or dependent employees of that country have provoked damage or have acted outside of the law, considering the expressions and resolutions of a municipal judge who wants to trample sovereignty.”

In Tennessee, incumbent Senator Lamar Alexander has defeated a tea party challenger in the state’s Republican primary. Tennessee Republican Rep. Scott DesJarlais appears to have defeated his challenger by only about 35 votes with all precincts reporting. DesJarlais made national headlines in 2012 after it emerged the anti-choice legislator had pressured his mistress to have an abortion.

The New York Times has ended its longstanding policy of avoiding the word “torture” to describe the CIA’s use of waterboarding and other techniques under its interrogation program. The Justice Department has denied the CIA’s actions met the legal definition of torture. But on Thursday, New York Times executive editor Dean Baquet wrote that since no one is facing prosecution, the current debate is less about the legal terms and more about whether the techniques were effective. He wrote: “So from now on, The Times will use the word 'torture' to describe incidents in which we know for sure that interrogators inflicted pain on a prisoner in an effort to get information.” Parts of a long-awaited Senate report on the CIA’s torture program are due out soon.