The United States has launched strikes against Islamic State militants in Syria. According to the Pentagon, the United States fired 47 Tomahawk missiles from warships as well as airstrikes from fighters, bombers and drones. According to the Syrian Observatory for Human Rights, at least 20 Islamic State fighters were killed in strikes that hit at least 50 targets in Raqqa and Deir al-Zor provinces in Syria’s east. U.S. Central Command said Bahrain, Jordan, Qatar, Saudi Arabia and the United Arab Emirates had either participated or supported the strikes against the Islamic State. The United States also acted alone against a separate militant organization known as the Khorasan group, saying it was taking action to disrupt “the imminent attack plotting against the United States and Western interests.” The Syrian Observatory for Human Rights said the strikes west of Aleppo killed 50 fighters as well as eight civilians, including three children. The Syrian government said the United States had informed it of the pending attacks hours before the strikes began. We will have more on Syria after headlines.

The strikes in Syria begin after six weeks of U.S. airstrikes have failed to significantly alter the landscape in Iraq, where the Islamic State has claimed vast swaths of territory. On Monday, reports emerged that dozens and potentially hundreds of Iraqi soldiers had been killed after militants overran a base north of Fallujah. An Iraqi lawmaker told The New York Times more than 300 soldiers died after the loss of Camp Saqlawiya. Meanwhile, the Islamic State has released a second propaganda video featuring British freelance journalist John Cantlie, in which Cantlie warns U.S. efforts in Iraq and Syria could become another Vietnam.

The French government has confirmed one of its citizens is being held hostage in Algeria by a group that claims ties to the Islamic State. The group, “Soldiers of the Caliphate,” has threatened to kill 55-year-old Hervé Gourdel unless France stops bombing Islamic State positions in Iraq. France launched the airstrikes on Friday. French Foreign Minister Laurent Fabius vowed the kidnapping would not change France’s involvement in the U.S.-led offensive.

Laurent Fabius: “Everything is being done in close cooperation with the Algerian authorities to obtain the release of our compatriot, but we must not hide the fact that the situation is extremely critical. France’s attitude remains the same: We intend to do the maximum needed to free the hostages, and more specifically, this hostage, but one terrorist group cannot influence France’s position.”

Here in New York, one day after the largest climate march in history, thousands of protesters marched on Wall Street Monday to highlight the role of corporations and capitalism in fueling climate change. At a protest dubbed “Flood Wall Street,” people sat down in the streets just blocks from the U.S. Stock Exchange. They remained for more than eight hours until police deployed pepper spray and began arresting more than 100 people. The action came ahead of today’s United Nations Climate Summit, where leaders from 125 nations will discuss an international agreement to cap record emissions of greenhouse gases. We will have more on the protest and today’s summit later in the broadcast.

The heirs of Standard Oil tycoon John D. Rockefeller have formally announced plans to purge their $860 million foundation of fossil fuel investments. At a news conference Monday, Stephen Heintz, president of the Rockefeller Brothers Fund, explained why Rockefeller’s heirs were moved to join the growing movement to divest.

Stephen Heintz: “The diversity of the people who were involved in this from every sector, from every walk of life, communities of just extraordinary diversity all across the country, tells me that this is getting to be more mainstream, which is very, very exciting. And the other thing is that it’s clear that there’s a moral imperative here. But there’s also an economic opportunity embedded in this, which gives people something positive to do.”

New data paints a much bleaker picture of the Ebola outbreak in West Africa. On Monday the World Health Organization predicted that without urgent improvements, there will be more than 20,000 cases of Ebola by early November, with thousands of deaths per week. Ebola is at risk of taking root and becoming endemic in West Africa. WHO strategy director Christopher Dye said Ebola is nowhere near under control.

Christopher Dye: “One of the key messages that we want to get across is that we are now in the third explosive phase of growth of the epidemic. This is exponential increase, with hundreds, going into thousands, of cases per week, and if we don’t stop the epidemic very soon, this is going to turn from a disaster into a catastrophe.”

The WHO’s official death toll has topped 2,800 with about 6,000 total cases, but that is likely a vast underestimation. A New York Times reporter who visited a cemetery in Freetown, the capital of Sierra Leone, reported 110 Ebola victims have been buried there in just over a week. By contrast, since the outbreak began, the country’s Health Ministry has confirmed just 10 deaths for the entire city and its suburbs. Sierra Leone recently imposed a lockdown and house-to-house searches, recording at least 130 new Ebola cases and 39 suspected cases.

Shiite Houthi rebels have seized new ground in the Yemeni capital Sana’a a day after signing a truce with the government. Sunday’s deal with the rebels calls for Yemen to form a new government following weeks of unrest. According to the Associated Press, 340 people have been killed in fighting over the past week alone. On Monday, the rebels captured the home of a top general as well as military bases and tanks.

Israeli forces say they have killed two people suspected of kidnapping and killing three Israeli teenagers in the West Bank in June. The teens’ disappearance prompted an Israeli raid in the West Bank and its ensuing assault on Gaza, which killed more than 2,100 Palestinians, most of them civilians. Israel originally blamed Hamas for the kidnappings, but later acknowledged Hamas leaders played no role. Today the Israeli military said it killed the two suspects in an exchange of fire in Hebron.

The Obama administration has unveiled new rules to combat corporate “tax inversions,” where companies move overseas to dodge U.S. taxes. Companies like Burger King, Medtronic and the drugmaker AbbVie have announced plans to relocate after buying foreign firms. Critics say the rules announced Monday by Treasury Secretary Jack Lew are not enough to end the practice, without involvement from Congress.

The Obama administration is increasing the U.S. nuclear arsenal despite President Obama’s public championing of disarmament. When Obama won the Nobel Peace Prize in 2008, the Nobel committee cited his steps toward reducing nuclear stocks around the world. But The New York Times reports Obama is overseeing extensive rebuilding of nuclear weapons at home, including at a new plant in Kansas City, dedicated last month, which is larger than the Pentagon and employs thousands of people. According to a recent federal study, the United is poised to spend up to $1.1 trillion over the next three decades on modernizing nuclear weapons.