In a detailed report, Josh Meyer explains how the Obama White House, for the sake of securing a nuclear deal with Tehran, stymied a major federal investigation that came close to dismantling the financing network of the Islamic Republic’s Lebanon-based proxy Hizballah.

The campaign, dubbed Project Cassandra, was launched in 2008 after the Drug Enforcement Administration (DEA) amassed evidence that Hizballah had transformed itself from a Middle East-focused military, political, [and terrorist] organization into an international crime syndicate that some investigators believed was collecting $1 billion a year from drug and weapons trafficking, money laundering, and other criminal activities.

Over the next eight years, agents . . . used wiretaps, undercover operations, and informants to map Hizballah’s illicit networks, with the help of 30 U.S. and foreign security agencies.

They followed cocaine shipments, some from Latin America to West Africa and on to Europe and the Middle East, and others through Venezuela and Mexico to the United States. They tracked the river of dirty cash as it was laundered by, among other tactics, buying American used cars and shipping them to Africa. And with the help of some key cooperating witnesses, the agents traced the conspiracy, they believed, to the innermost circle of Hizballah and its state sponsor, Iran.

But as Project Cassandra reached higher into the hierarchy of the conspiracy, Obama administration officials threw an increasingly insurmountable series of roadblocks in its way, according to interviews with dozens of participants who in many cases spoke for the first time about events shrouded in secrecy, and a review of government documents and court records. When Project Cassandra’s leaders sought approval for some significant investigations, prosecutions, arrests, and financial sanctions, officials at the Justice and Treasury Departments delayed, hindered, or rejected their requests.

Among those active in protecting Hizballah was John Brennan, Barack Obama’s senior counterterrorism adviser and later CIA director, who argued that there were “moderate elements” within the terrorist group that the U.S. should strengthen.

In the course of the investigation, agents working with Cassandra uncovered Hizballah’s role in providing Iraqi insurgents with the sophisticated explosives that they used to kill hundreds of American soldiers. The same arms-trafficking network also supplied Iran with parts for its illegal nuclear and ballistic-missile programs. At its head was one Ali Fayad, who worked for the Russian-backed Yanukovych regime in Ukraine and was Vladimir Putin’s chief arms dealer, responsible for getting weapons to Syria to aid Bashar al-Assad. When DEA officials had Fayad in their sights, and pressured the State Department to arrange for his extradition, Foggy Bottom demurred.

On Tuesday, a Hizballah drone attack injured three people in northern Israel. The next day, another attack, targeting an IDF base, injured eighteen people, six of them seriously, in Arab al-Amshe, also in the north. This second attack involved the simultaneous use of drones carrying explosives and guided antitank missiles. In both cases, the defensive systems that performed so successfully last weekend failed to stop the drones and missiles. Ron Ben-Yishai has a straightforward explanation as to why: the Lebanon-backed terrorist group is getting better at evading Israel defenses. He explains the three basis systems used to pilot these unmanned aircraft, and their practical effects:

These systems allow drones to act similarly to fighter jets, using “dead zones”—areas not visible to radar or other optical detection—to approach targets. They fly low initially, then ascend just before crashing and detonating on the target. The terrain of southern Lebanon is particularly conducive to such attacks.

But this requires skills that the terror group has honed over months of fighting against Israel. The latest attacks involved a large drone capable of carrying over 50 kg (110 lbs.) of explosives. The terrorists have likely analyzed Israel’s alert and interception systems, recognizing that shooting down their drones requires early detection to allow sufficient time for launching interceptors.

The IDF tries to detect any incoming drones on its radar, as it had done prior to the war. Despite Hizballah’s learning curve, the IDF’s technological edge offers an advantage. However, the military must recognize that any measure it takes is quickly observed and analyzed, and even the most effective defenses can be incomplete. The terrain near the Lebanon-Israel border continues to pose a challenge, necessitating technological solutions and significant financial investment.