It’s been three days now since coordinated terrorist attacks shook Paris, and the rest of the world. 

Over the past 24 hours, we’ve learned a lot about the forces behind it and leaders around the globe are taking action.

French President Francois Hollande announced today that France is at war and will intensify its operations in Syria, which he called “the biggest factory of terrorists the world has known.”

Overnight, they carried out 168 in-county raids and more than 100 people are now under house arrest in France. 

Meanwhile, the search for others involved continues in several different countries, including Turkey and Belgium, where there were more arrests.  And the U.S. has announced a new intelligence-sharing agreement with France.

"The attacks in Paris remind us that it will not be enough to defeat ISIL in Syria and Iraq alone. Our nations, therefore, committed to strengthening border controls, sharing more information and stepping up our efforts to prevent the flow of foreign fighters in and out of Syria and Iraq."

Both the U.S. and France have been carrying out major airstrikes in Syria over the past two days.

Meanwhile, ISIS is promising future attacks, including in our nation’s capital.

Former Massachusetts Secretary of Public Safety AndreaCabral, terrorism expert at Brandeis University and founder of the Western Jihadism Project JytteKlausen and WGBH News Analyst and GroundTruth Project Head Charlie Sennott(@CMSennott) discuss.