Here's what we know so far
: During a raid Tuesday at an apartment in the Forest district of Brussels, one suspected jihadist -- Mohamed Belkaid, an Algerian national -- shot it out with Belgian authorities, holding police officers at bay with an AK-47. A police sniper killed Belkaid, but not before two people escaped out the back and across nearby rooftops. The deceased Belkaid reportedly appeared on a list of would-be suicide bombers. The list was acquired by NBC News from a Syrian who claimed to have stolen it from the Islamic State.
Belgian authorities believe it was Abdeslam and an accomplice who were flushed out of the apartment during that Tuesday gunbattle. In the raid's aftermath, counterterrorism police were able to track Abdeslam to the Molenbeek neighborhood of Brussels, where he and four others were taken into custody in a tactical operation Friday involving exchanges of gunfire and explosions.
On the one hand, Abdeslam's capture marks a critical milestone, as it closes a chapter of the horrific Paris terrorist attacks of November 13, 2015, that killed 130 people. French authorities briefly, but unknowingly, had Abdeslam in their grasp hours after the attacks, at the Belgian border, and they let him go. This police blunder was followed by dozens of raids over the course of four months to finally find Abdeslam and any suspected co-conspirators.
Now there is a chance for some measure of justice for the victims of the November attacks in Paris.
From a counterterrorism perspective, the capture of Abdeslam could provide enormously useful information.
As a suspected jihadist who allegedly executed a mass casualty attack in France's capital with ties to individuals who trained with ISIS in Syria, he may know a great deal about senior ISIS leadership.
Abdeslam could also provide tremendous insight into current and future jihadist threats against the entire European Union. He could walk French and Belgian authorities through every stage of his alleged plotting, including any direct communications with ISIS leadership or facilitators in Syria.
On the European side of the equation, Abdeslam could lay out the logistics and travel networks, operational security measures, and target surveillance he and any other suspected jihadists allegedly utilized to conduct the November attacks. All of this would be essential information that could save lives in the future.
Whether Abdeslam -- or any of the other four suspects taken into custody -- have knowledge of active terrorist cells or operational plots remains to be seen. Belgian and French authorities, however, will no doubt have new phone numbers to trace, computer hard drives to analyze and names to track down. In the coming days, we will have a clearer picture of just how large the November 13 terror network really was, and whether it remains active.
But much of this is contingent upon Abdeslam talking to authorities, which is far from a given. The horrific nature of his alleged crimes certainly warrantsa life sentence in prison, so sentence mitigation isn't much incentive. Belgian and French security officials will have to rely on savvy interrogation and whatever legal means of coercion and inducement are at their disposal to get answers from Abdeslam.
Receiving cooperation from a reportedly hardened jihadist whose brother blew himself up on November 13 -- and who was reportedly hours away from becoming a suicide bomber himself -- will likely be a slow, difficult task.
In addition, there will be scrutiny of the Muslim community of Molenbeek -- an area already known to be a hotbed of Islamic radicalism -- in the aftermath of these raids. That Abdeslam -- referred to in the press as "Europe's most wanted man" -- could have successfully hidden not just in a suburb of Belgium's capital city, but in the very neighborhood most likely to harbor jihadists -- and done so for four months -- is deeply troubling. Some suspects are already in Belgian custody for their alleged role in providing a safe haven to Abdeslam.
The possibility remains that there were others who at least knew of Abdeslam's whereabouts, and kept silent.
Nonetheless, today was a victory for France, Belgium and the civilized world against jihadist terrorism. But, as is the case with every individual raid or arrest, it is but one victory in a much larger and ongoing war.
Perhaps the most important outcome of today's arrests will be that Europe's counterterrorism forces will achieve a better understanding of the full scope of the Islamic State's plotting against the West -- and how to stop it before there is another terrorist atrocity on Europe's soil.